Method of high power laser-mechanical drilling

ABSTRACT

There is provided a laser-mechanical method for drilling boreholes that utilizes specific combinations of high power directed energy, such as laser energy, in combination with mechanical energy to provide a synergistic enhancement of the drilling process.

This application: (i) claims, under 35 U.S.C. §119(e)(1), the benefit ofthe filing date of Feb. 24, 2011 of U.S. provisional application Ser.No. 61/446,041; (ii) claims, under 35 U.S.C. §119(e)(1), the benefit ofthe filing date of Feb. 24, 2011 of U.S. provisional application Ser.No. 61/446,312; (iii) claims, under 35 U.S.C. §119(e)(1), the benefit ofthe filing date of Feb. 24, 2011 of U.S. provisional application Ser.No. 61/446,040; (iv) claims, under 35 U.S.C. §119(e)(1), the benefit ofthe filing date of Feb. 24, 2011 of U.S. provisional application Ser.No. 61/446,043; (v) claims, under 35 U.S.C. §119(e)(1), the benefit ofthe filing date of Feb. 24, 2011 of U.S. provisional application Ser.No. 61/446,042; (vi) is a continuation-in-part of U.S. patentapplication Ser. No. 12/544,038 filed Aug. 19, 2009, which claims under35 U.S.C. §119(e)(1) the benefit of the filing date of Feb. 17, 2009 ofU.S. provisional application Ser. No. 61/153,271, the benefit of thefiling date of Oct. 17, 2008 of U.S. provisional application Ser. No.61/106,472, the benefit of the filing date of Oct. 3, 2008 of U.S.provisional application Ser. No. 61/102,730, and the benefit of thefiling date of Aug. 20, 2008 of U.S. provisional application Ser. No.61/090,384; (vii) is a continuation-in-part of U.S. patent applicationSer. No. 12/543,968 filed Aug. 19, 2009; and (viii) is acontinuation-in-part of U.S. patent application Ser. No. 12/543,986filed Aug. 19, 2009, which claims under 35 U.S.C. §119(e)(1) the benefitof the filing date of Feb. 17, 2009 of U.S. provisional application Ser.No. 61/153,271, the benefit of the filing date of Oct. 17, 2008 of U.S.provisional application Ser. No. 61/106,472, the benefit of the filingdate of Oct. 3, 2008 of U.S. provisional application Ser. No.61/102,730, and the benefit of the filing date of Aug. 20, 2008 of U.S.provisional application Ser. No. 61/090,384, the entire disclosures ofeach of which are incorporated herein by reference.

This invention was made with Government support under Award DE-AR0000044awarded by the Office of ARPA-E U.S. Department of Energy. TheGovernment has certain rights in this invention.

BACKGROUND OF THE INVENTION Field of the Invention

The present inventions relate to high power laser energy tools andsystems and methods.

As used herein, unless specified otherwise, “high power laser energy”means a laser beam having at least about 1 kW (kilowatt) of power. Asused herein, unless specified otherwise “great distances” means at leastabout 500 m (meter). As used herein the term “substantial loss ofpower,” “substantial power loss” and similar such phrases, mean a lossof power of more than about 3.0 dB/km (decibel/kilometer) for a selectedwavelength. As used herein the term “substantial power transmission”means at least about 50% transmittance.

As used herein, unless specified otherwise, the term “earth” should begiven its broadest possible meaning, and includes, the ground, allnatural materials, such as rocks, and artificial materials, such asconcrete, that are or may be found in the ground, including withoutlimitation rock layer formations, such as, granite, basalt, sandstone,dolomite, sand, salt, limestone, rhyolite, quartzite and shale rock.

As used herein, unless specified otherwise, the term “borehole” shouldbe given it broadest possible meaning and includes any opening that iscreated in a material, a work piece, a surface, the earth, a structure(e.g., building, protected military installation, nuclear plant,offshore platform, or ship), or in a structure in the ground, (e.g.,foundation, roadway, airstrip, cave or subterranean structure) that issubstantially longer than it is wide, such as a well, a well bore, awell hole, a micro hole, slimhole, a perforation and other termscommonly used or known in the arts to define these types of narrow longpassages. Wells would further include exploratory, production,abandoned, reentered, reworked, and injection wells. Although boreholesare generally oriented substantially vertically, they may also beoriented on an angle from vertical, to and including horizontal. Thus,using a vertical line, based upon a level as a reference point, aborehole can have orientations ranging from 0° i.e., vertical, to90°,i.e., horizontal and greater than 90° e.g., such as a heel and toeand combinations of these such as for example “U” and “Y” shapes.Boreholes may further have segments or sections that have differentorientations, they may have straight sections and arcuate sections andcombinations thereof; and for example may be of the shapes commonlyfound when directional drilling is employed. Thus, as used herein unlessexpressly provided otherwise, the “bottom” of a borehole, the “bottomsurface” of the borehole and similar terms refer to the end of theborehole, i.e., that portion of the borehole furthest along the path ofthe borehole from the borehole's opening, the surface of the earth, orthe borehole's beginning. As used herein unless specified otherwise, theterms “side” and “wall” of a borehole should to be given their broadestpossible meaning and include the longitudinal surfaces of the borehole,whether or not casing or a liner is present, as such, these terms wouldinclude the sides of an open borehole or the sides of the casing thathas been positioned within a borehole. Boreholes may be made up of asingle passage, multiple passages, connected passages and combinationsthereof, in a situation where multiple boreholes are connected orinterconnected each borehole would have a borehole bottom. Boreholes maybe formed in the sea floor, under bodies of water, on land, in iceformations, or in other locations and settings.

Boreholes are generally formed and advanced by using mechanical drillingequipment having a rotating drilling tool, e.g., a bit. For example andin general, when creating a borehole in the earth, a drilling bit isextending to and into the earth and rotated to create a hole in theearth. In general, to perform the drilling operation the bit must beforced against the material to be removed with a sufficient force toexceed the shear strength, compressive strength or combinations thereof,of that material. Thus, in conventional drilling activity mechanicalforces exceeding these strengths of the rock or earth must be applied.The material that is cut from the earth is generally known as cuttings,e.g., waste, which may be chips of rock, dust, rock fibers and othertypes of materials and structures that may be created by the bit'sinteractions with the earth. These cuttings are typically removed fromthe borehole by the use of fluids, which fluids can be liquids, foams orgases, or other materials know to the art.

As used herein, unless specified otherwise, the term “advancing” aborehole should be given its broadest possible meaning and includesincreasing the length of the borehole. Thus, by advancing a borehole,provided the orientation is not horizontal, e.g., less than 90° thedepth of the borehole may also be increased. The true vertical depth(“TVD”) of a borehole is the distance from the top or surface of theborehole to the depth at which the bottom of the borehole is located,measured along a straight vertical line. The measured depth (“MD”) of aborehole is the distance as measured along the actual path of theborehole from the top or surface to the bottom. As used herein unlessspecified otherwise the term depth of a borehole will refer to MD. Ingeneral, a point of reference may be used for the top of the borehole,such as the rotary table, drill floor, well head or initial opening orsurface of the structure in which the borehole is placed.

As used herein, unless specified otherwise, the terms “ream”, “reaming”,a borehole, or similar such terms, should be given their broadestpossible meaning and includes any activity performed on the sides of aborehole, such as, e.g., smoothing, increasing the diameter of theborehole, removing materials from the sides of the borehole, such ase.g., waxes or filter cakes, and under-reaming.

As used herein, unless specified otherwise, the terms “drill bit”,“bit”, “drilling bit” or similar such terms, should be given theirbroadest possible meaning and include all tools designed or intended tocreate a borehole in an object, a material, a work piece, a surface, theearth or a structure including structures within the earth, and wouldinclude bits used in the oil, gas and geothermal arts, such as fixedcutter and roller cone bits, as well as, other types of bits, such as,rotary shoe, drag-type, fishtail, adamantine, single and multi-toothed,cone, reaming cone, reaming, self-cleaning, disc, three cone, rollingcutter, crossroller, jet, core, impreg and hammer bits, and combinationsand variations of the these.

Mechanical bits cut rock with shear stresses created by rotating acutting surface against the rock and placing a large amount ofweight-on-bit (“WOB”). Mechanical bits cut rock by applying crushing(compressive) and/or shear stresses created by rotating a cuttingsurface against the rock and placing a large amount of WOB. In the caseof a bit made of the material polycrystalline diamond compact (“PDC”),e.g., a PDC bit, this action is primarily by shear stresses and in thecase of roller cone bits this action is primarily by crushing(compression) and shearing stresses. For example, the WOB applied to an8¾″ PDC bit may be up to 15,000 lbs, and the WOB applied to an 8¾″roller cone bit may be up to 60,000 lbs. When mechanical bits are usedfor drilling hard and ultra-hard rock excessive WOB, rapid bit wear, andlong tripping times result in an effective drilling rate that isessentially economically unviable. The effective drilling rate is basedupon the total time necessary to complete the borehole and, for example,would include time spent tripping in and out of the borehole, as wellas, the time for repairing or replacing damaged and worn bits.

As used herein, unless specified otherwise, the term “drill pipe” shouldbe given its broadest possible meaning and includes all forms of pipeused for drilling activities; and refers to a single section or piece ofpipe. As used herein the terms “stand of drill pipe,” “drill pipestand,” “stand of pipe,” “stand” and similar type terms are to be giventheir broadest possible meaning and include two, three or four sectionsof drill pipe that have been connected, e.g., joined together, typicallyby joints having threaded connections. As used herein the terms “drillstring,” “string,” “string of drill pipe,” string of pipe” and similartype terms are to be given their broadest definition and would include astand or stands joined together for the purpose of being employed in aborehole. Thus, a drill string could include many stands and manyhundreds of sections of drill pipe.

As used herein, unless specified otherwise, the term “tubular” should begiven its broadest possible meaning and includes drill pipe, casing,riser, coiled tube, composite tube, vacuum insulated tubing (“VIT),production tubing and any similar structures having at least one channeltherein that are, or could be used, in the drilling industry. As usedherein the term “joint” is to be given its broadest possible meaning andincludes all types of devices, systems, methods, structures andcomponents used to connect tubulars together, such as for example,threaded pipe joints and bolted flanges. For drill pipe joints, thejoint section typically has a thicker wall than the rest of the drillpipe. As used herein the thickness of the wall of tubular is thethickness of the material between the internal diameter of the tubularand the external diameter of the tubular.

SUMMARY

There has been a long-standing need for rapidly and efficiently drillingboreholes into hard and very hard materials, and to do so with minimaldamage to the drilling bit. The present inventions, among other things,solve these and other needs by providing the articles of manufacture,devices and processes taught herein.

Thus, there is provided herein a method of directed energy mechanicaldrilling having the steps of: providing directed energy to a surface ofa material; providing mechanical energy to that surface; so that theratio of directed energy to mechanical energy is greater than about 5;and, in this manner a borehole is advance through the surface of thematerial.

Further, there is provided a method directed energy mechanical drillinghaving steps including: providing directed energy to a surface of amaterial; providing mechanical energy to the surface; so that the ratioof directed energy to mechanical energy is greater than about 10; and,in this manner a borehole is advance through the surface of thematerial.

Moreover, there is provided a method of directed energy mechanicaldrilling including the following: providing directed energy to a surfaceof a material; providing mechanical energy to the surface; so that theratio of directed energy to mechanical energy is greater than about 20;and, in this manner a borehole is advance through the surface of thematerial.

Still further, there is provided a method of providing directed energyto a surface of a material and providing mechanical energy to thesurface; in a manner where the ratio of directed energy to mechanicalenergy is greater than about 40; and, in this manner a borehole isadvance through the surface of the material.

Further still, there is provided directed energy mechanical drilling bydirecting directed energy to a surface of a material and directingmechanical energy to the surface in a ratio of directed energy tomechanical energy that is greater than about 2 and this manner aborehole is advance through the surface of the material.

Additionally, there is provided a method of directed energy mechanicaldrilling having the steps of: providing high power laser directed energyto a surface of a material; providing mechanical energy to the surface;and, so that the ratio of high power laser directed energy to mechanicalenergy is greater than about 5; and, in this manner a borehole isadvance through the surface of the material.

Yet still additionally, there is provided a directed energy mechanicaldrilling method of providing high power laser directed energy to asurface of a material; providing mechanical energy to the surface; inthe ratio of high power laser directed energy to mechanical energy thatis greater than about 10; and, thus advancing a borehole through thesurface of the material.

Additionally, there is provided a method of directed energy mechanicaldrilling by providing high power laser directed energy to a surface of amaterial, providing mechanical energy to the surface, so that the ratioof high power laser directed energy to mechanical energy is greater thanabout 20; and, in this manner a borehole is advance through the surfaceof the material.

Still further, there is provided a method of directed energy mechanicaldrilling having steps including: providing high power laser directedenergy to a surface of a material; providing mechanical energy to thesurface; and, so that the ratio of high power laser directed energy tomechanical energy is greater than about 40; and, in this manner aborehole is advance through the surface of the material.

Yet additionally, there is provided a directed energy mechanicaldrilling method by providing high power laser directed energy to asurface; providing mechanical energy to the surface; in a ratio ofdirected energy to mechanical energy that is greater than about 2 and,thus advancing a borehole through the surface of the material areutilized.

Still further, the methods may also include steps, conditions andparameters in which: the directed energy is high power laser energy andin which the high power laser directed energy has a power of at leastabout 40 kW; the surface is not substantially melted by the laserenergy; the mechanical energy is provided by a bit having aweight-on-bit less than about 2000 pounds; the mechanical energy isprovided by a bit having a weight-on-bit less than about 1000 pounds;the mechanical energy is provided by a bit having a weight-on-bit lessthan about 2000 pounds so that the borehole is advanced at a rate ofpenetration of at least about 10 feet per hour; the mechanical energy isprovided by a bit having a weight-on-bit less than about 2000 pounds sothat the borehole is advanced at a rate of penetration of at least about10 feet per hour; the high power laser directed energy has a power of atleast about 20 kW and the mechanical energy is provided by a bit havinga weight-on-bit less than about 2000 pounds so that the borehole isadvanced at a rate of penetration of at least about 20 feet per hour;the high power laser directed energy has a power of at least about 20 kWand the mechanical energy is provided by a bit having a weight-on-bitless than about 2000 pounds so that the borehole is advanced at a rateof penetration of at least about 20 feet per hour; the high power laserdirected energy has a power of at least about 20 kW and the mechanicalenergy is provided by a bit having a weight-on-bit less than about 2000pounds so that the borehole is advanced at a rate of penetration of atleast about 20 feet per hour; the high power laser directed energy has apower of at least about 50 kW and the mechanical energy is provided by abit having a weight-on-bit less than about 2000 pounds so that theborehole is advanced at a rate of penetration of at least about 20 feetper hour; the mechanical energy is provided by a bit having aweight-on-bit less than about 2000 pounds so that the borehole isadvanced at a rate of penetration the rate of penetration of at leastabout 20 feet per hour through material having an average hardness ofabout 20 ksi (kilopound per square inch) or greater; the borehole isadvanced for greater than about 500 feet; and the borehole is advancedfor greater than about 5,000 feet.

Moreover, there is provided a method of advancing borehole in the earthusing high power laser mechanical drilling techniques, the methodinvolving: directing laser energy, in a moving pattern, to a bottomsurface of a borehole in the earth; heating the earth with the directedlaser energy to a point below the melting point; providing mechanicalenergy to the heated earth; so that the ratio of laser energy tomechanical energy is greater than about 2; and, in this manner theborehole is advanced

Furthermore, the methods may also include steps, conditions andparameters in which: the laser energy has a power of about 20 kW orgreater; the power/area of the laser energy on the surface of the bottomof the borehole is about 50 W/cm² or greater; the power/area of thelaser energy on the surface of the bottom of the borehole is about 75W/cm² or greater; the power/area of the laser energy on the surface ofthe bottom of the borehole is about 100 W/cm² or greater; the laserenergy on the surface of the bottom of the borehole is about 200 W/cm²or greater; the power/area of the laser energy on the surface of thebottom of the borehole is about 300 W/cm² or greater; the mechanicalenergy is provided by a bit having a weight-on-bit less than about 2000pounds; the mechanical energy is provided by a bit having aweight-on-bit less than about 1000 pounds; the mechanical energy isprovided by a bit having a weight-on-bit less than about 2000 pounds andso that the borehole is advanced at a rate of penetration of at leastabout 10 feet per hour; the mechanical energy is provided by a bithaving a weight-on-bit, so that the weight-on-bit is less than about2000 pounds and so that the borehole is advanced at a rate ofpenetration of at least about 20 feet per hour; the mechanical energy isprovided by a bit having a weight-on-bit less than about 2000 pounds andso that borehole is advances at a rate of penetration of at least about10 feet per hour through material having an average hardness of about 20ksi or greater; the mechanical energy is provided by a bit having aweight-on-bit less than about 2000 pounds and so that the borehole isadvanced at a rate of penetration of at least about 20 feet per hourthrough material having an average hardness of about 20 ksi or greater;and the borehole is advanced for greater than about 1,000 feet, greaterthan about 2,000 feet, and greater than then about 5,000 feet andgreater than about 10,000 feet.

Moreover, there is provided a method of laser-mechanical drilling aborehole in a formation having at least 500 feet of material having ahardness greater than about 30 ksi by: providing a laser-mechanical bitinto a borehole, the laser-mechanical bit in optical communication witha high power laser beam source; rotating the laser-mechanical bitagainst a surface of the borehole while propagating a laser beam againstthe borehole surface; with an RPM of from about 240 to about 720, a WOBof less than about 2,000 lbs, a DE Power/Area of about 90 W/cm² to about560 W/cm², and an ME Power/Area of about 4 W/cm² to about 250 W/cm²; andin this manner the borehole is advanced at an ROP of at least about 10ft/hr.

Further, there is provided a method of laser-mechanical drilling aborehole in a formation having at least 500 feet of material having ahardness greater than about 30 ksi by: providing a laser-mechanical bitinto a borehole, the laser-mechanical bit in optical communication witha high power laser beam source; rotating the laser-mechanical bitagainst a surface of the borehole while propagating a laser beam againstthe borehole surface; with an RPM of from about 600 to about 800, a WOBof less than about 5,000 lbs, a DE Power/Area of about 40 W/cm² to about250 W/cm², and an ME Power/Area of about 200 W/cm² to about 3000 W/cm²;and, in this manner the borehole is advanced at an ROP of at least about15 ft/hr.

Additionally, there is provided a method of laser-mechanical drilling aborehole in a formation having at least 500 feet of material having ahardness greater than about 20 ksi by: providing a laser-mechanical bitinto a borehole, the laser-mechanical bit in optical communication witha high power laser beam source; rotating the laser-mechanical bitagainst a surface of the borehole while propagating a laser beam againstthe borehole surface; with an RPM of from about 600 to about 1250, a WOBof from about 500 to about 5,000 lbs, a DE Power/Area of about 90 W/cm²to about 570 W/cm², and an ME Power/Area of about 40 W/cm² to about 270W/cm²; and in this manner the borehole is advanced at an ROP of at leastabout 10.

Yet additionally, there is provided a method of laser-mechanicaldrilling a borehole in a formation having at least 500 feet of hard rockmaterial, having a hardness greater than about 20 ksi by: providing alaser-mechanical bit into a borehole, the laser-mechanical bit inoptical communication with a high power laser beam source; rotating thelaser-mechanical bit against a surface of the borehole with an RPM ofabout 250, a WOB of from about 1,000 lbs, a DE Power/Area of about 370W/cm², and an ME Power/Area of about 40 W/cm²; and, in this manner theborehole is advanced at an ROP of at least about 20 ft/hr.

Yet still further, there is provided a method of laser-mechanicaldrilling a borehole in a formation having at least 500 feet of hard rockmaterial, having a hardness greater than about 20 ksi, the method havingthe steps of: providing a laser-mechanical bit into a borehole, thelaser-mechanical bit in optical communication with a high power laserbeam source; rotating the laser-mechanical bit against a surface of theborehole with an RPM of from about 720, a WOB of from about 2,000 lbs, aDE Power/Area of about 190 W/cm², and an ME Power/Area of about 250W/cm²; and, in this manner the borehole is advanced at an ROP of atleast about 50 ft/hr.

Further still, there is provided a method of laser-mechanical drilling aborehole in a formation having at least 500 feet of hard rock material,having a hardness greater than about 20 ksi by: providing alaser-mechanical bit into a borehole, the laser-mechanical bit inoptical communication with a high power laser beam source; rotating thelaser-mechanical bit against a surface of the borehole with an RPM offrom about 720, a WOB of from about 2,000 lbs, a DE Power/Area of about370 W/cm², and an ME Power/Area of about 250 W/cm²; and, in this mannerthe borehole is advanced at an ROP of at least about 50 ft/hr.

Still further, there is provided a method of laser-mechanical drilling aborehole in a formation having at least 500 feet of hard rock material,having a hardness greater than about 20 ksi by: providing alaser-mechanical bit into a borehole, the laser-mechanical bit inoptical communication with a high power laser beam source; rotating thelaser-mechanical bit against a surface of the borehole with an RPM offrom about 720, a WOB of from about 5,000 lbs, a DE Power/Area of about290 W/cm², and an ME Power/Area of about 240 W/cm²; and, in this mannerthe borehole is advanced at an ROP of at least about 20 ft/hr.

Moreover, there is provided a method of laser-mechanical drilling aborehole in a formation having at least 500 feet of hard rock material,having a hardness greater than about 20 ksi, this method includes:providing a laser-mechanical bit into a borehole, the laser-mechanicalbit in optical communication with a high power laser beam source;rotating the laser-mechanical bit against a surface of the borehole withan RPM of from about 1,200, a WOB of from about 500 lbs, a DE Power/Areaof about 470 W/cm², and an ME Power/Area of about 100 W/cm²; and, inthis manner the borehole is advanced at an ROP of at least about 30ft/hr.

Still further, a method of laser-mechanical drilling a borehole in aformation having at least 500 feet of hard rock material, having ahardness greater than about 20 ksi, by: providing a laser-mechanical bitinto a borehole, the laser-mechanical bit in optical communication witha high power laser beam source; rotating the laser-mechanical bitagainst a surface of the borehole with an RPM of from about 720, a WOBof from about 2,000 lbs, a DE Power/Area of about 470 W/cm², and an MEPower/Area of about 250 W/cm²; and, in this manner the borehole isadvanced at an ROP of at least about 30 ft/hr.

Furthermore, there is also provided a method of laser-mechanicaldrilling a borehole in a formation by: providing a laser-mechanical bitinto a borehole, the laser-mechanical bit in optical communication witha high power laser beam source; applying from the high power laser beamsource a high power laser beam to a surface of the borehole, so that thehigh power laser beam generates an intensity ranging from about 150 toabout 250 W/cm² on a surface of the borehole for an elapsed timesufficient to cause a surface temperature rise in the range from about400 degrees C. to about 1,000 degrees C. and thus forming a laserapplied surface; and applying a mechanical force to the laser appliedsurface, so that the mechanical force generates an intensity rangingfrom about 30 to about 250 W/cm² to remove the laser applied surface ofthe borehole.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a perspective view of an embodiment of a fixed cutterlaser-mechanical bit in accordance with the present invention.

FIG. 1B is a bottom view of the bit of FIG. 1A.

FIG. 1C is a cross section view of the bit of FIGS. 1A and 1B takenalong line 1C-1C.

FIG. 2 is a schematic of an embodiment of a high power laser drilling,workover and completion unit in accordance with the present invention.

FIG. 3 is a chart showing various directed energy regimes.

FIG. 4 is schematic of chips of basalt.

FIG. 5 is a schematic of chips of dolomite.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present inventions relate to directed energy mechanical drillingmethods that utilize high power directed energy in conjunction withmechanical forces. These methods may find uses in many different typesof materials and structures, such as metal, stone, composites, concrete,the earth, and structures in the earth. In particular, these methods mayfind preferable uses in situations and environments where advancing aborehole with conventional, e.g., non-directed energy technology, wasdifficult or impossible, because, for example, the remoteness of thearea where the borehole was to be advanced, difficult environmentalconditions or other factors that placed great, and at timesinsurmountable burdens on conventional drilling or boring technologies.These methods also find preferable uses in situations where reducednoise and vibrations, compared to conventional technologies, aredesirable or a requisite.

In general, the present methods involve the application of directedenergy and mechanical forces to a surface, e.g., the bottom of aborehole, to remove material and advance the borehole. The directedenergy and mechanical forces are preferably applied in a rotating orrevolving manner, so that they are so moved about or on the surface tobe drilled (i.e., the drilling surface), e.g., the bottom of a borehole.“Directed energy” would include, for example, optical laser energy,non-optical laser energy, microwaves, sound waves, plasma, electricarcs, flame, flame jets, steam and combinations of the foregoing, aswell as, water jets (although a water jet may be viewed as having amechanical interaction with the drilling surface, for the purpose ofthis specification it will be characterized amongst the group ofdirected energies, based upon the following specific definition ofmechanical energy), and other forms of energy that are not “mechanicalenergy” as defined in these specifications. “Mechanical energy,” as usedherein, is limited to energy that is transferred to the drilling surfaceby the interaction or contact of a solid object, e.g., a drill bitcutter, roller cone, or a saw blade, with the drilling surface.

These methods provide for the application of unique combinations ofdirected energy and mechanical force to obtain a synergism. Thissynergism enables these methods to advance boreholes through very hardmaterials, such as hard rocks and ultra hard rocks, with very low WOB,e.g., less than about 5,000 lbs, less than about 2000 lbs and preferablyabout 1000 lbs or less. This reduction in WOB has the potential benefitof providing for substantially longer drilling bit life, longer drillingtimes where the bit can remain in the borehole, and reduced tripping,which in turn has the potential to greatly reduce the cost of drilling aborehole. In addition to reducing WOB, in other processes, such as in acutting application, the associated mechanical forces that are neededmay similarly be greatly reduced.

In general, and using drilling a borehole in the earth as anillustrative example, as the bit is rotated in the bottom of theborehole, the directed energy is propagated at the bottom surface (andpotentially side and gauge surfaces). The directed energy weakens (andmay also partially remove, and remove) the material so contacted, i.e.,directed energy affected material. The mechanical devices, e.g.,cutters, then rotate in the borehole, contacting and removing thedirected energy affected material (and potentially some additionalmaterial). However, it is preferable, as shown by the examples below,that the mechanical cutter, and the mechanical energy that it delivers,is only sufficient to remove the directed energy affected material. Inthis way the life of the cutters is preserved, damage is minimized, andthe amount of heat built up from friction is controlled and preferablyin some embodiments kept to a minimum.

Preferably, in these methods the source of directed energy is a highpower laser beam. Thus, and more preferably the laser beam, or beams,may have 10 kW, 20 kW, 40 kW, 80 kW or more power; and have a wavelengthin the range of from about 445 nm (nanometers) to about 2100 nm,preferably in the range of from about 800 to 1900 nm, and morepreferably in the ranges of from about 1530 nm to 1600 nm, from about1060 nm to 1080 nm, and from about 1800 nm to 1900 nm. Further, thetypes of laser beams and sources for providing a high power laser beammay be the devices, systems, optical fibers and beam shaping anddelivery optics that are disclosed and taught in the following US patentapplications and US Patent Application Publications: Publication No. US2010/0044106, Publication No. US 2010/0044105, Publication No. US2010/0044103, Publication No. US 2010/0044102, Publication No. US2010/0215326, Publication No. 2012/0020631, Ser. No. 13/210,581, andSer. No. 61/493,174, the entire disclosures of each of which areincorporated herein by reference. The source for providing rotationalmovement may be a string of drill pipe rotated by a top drive or rotarytable, a down hole mud motor, a down hole turbine, a down hole electricmotor, and, in particular, may be the systems and devices disclosed inthe following US patent applications and US Patent ApplicationPublications: Publication No. US 2010/0044106, Publication No. US2010/0044104, Publication No. US 2010/0044103, Ser. No. 12/896,021, Ser.No. 61/446,042 and Ser. No. 13/211,729, the entire disclosures of eachof which are incorporated herein by reference. The high power lasers forexample may be fiber lasers or semiconductor lasers having 10 kW, 20 kW,50 kW or more power and, which emit laser beams with wavelengthspreferably in about the 1064 nm range, about the 1070 nm range, aboutthe 1360 nm range, about the 1455 nm range, about the 1550 nm range,about the 1070 nm range, about the 1083 nm range, or about the 1900 nmrange (wavelengths in the range of 1900 nm may be provided by Thuliumlasers). Thus, by way of example, there is contemplated the use of four,five, or six, 20 kW lasers to provide a laser beam in a bit having apower greater than about 60 kW, greater than about 70 kW, greater thanabout 80 kW, greater than about 90 kW and greater than about 100 kW. Onelaser may also be envisioned to provide these higher laser powers.

Preferably, the source of mechanical energy is a fixed cutter drill bitor roller cone used as part of a laser-mechanical bit. In general, thecomponents of a laser mechanical bit may be made from materials that areknown to those of skill in the art for such applications or components,or that are later developed for such applications. For example, the bitbody may be made from steel, preferably a high-strength, weldable steel,such as SAE 9310, or cemented carbide matrix material. The blades may bemade from similar types of material. The blades and the bit body may bemade, for example by milling, from a single piece of metal, or they maybe separately made and affixed together. The cutters may be made fromfor example, materials such as polycrystalline diamond compact (“PDC”),grit hotpressed inserts (“GHI”), and other materials known to the art orlater developed by the art. Cutters are commercially available from forexample US Synthetic, MegaDiamond, and Element 6. The roller cone armsmay be made from steel, such as SAE 9310. Like the blades, the arms andthe bit body may be made from a single piece of metal, or they may bemade from separate pieces of metal and affixed together. Roller coneinserts, for example, may be made from sintered tungsten carbide insert(“TCI”) or the roller cones may be made with milled teeth (“MTs”).Roller cones, roller cone inserts, and roller cones and leg assemblies,may be obtained commercially from Varel International, while TCI may beobtained from for example Kennametal or ATI Firth Sterling. It ispreferred that the inner surface of the beam path be made of materialthat does not absorb the laser energy, and thus, it is preferable thatsuch surfaces be reflective or polished surfaces. It is also preferredthat any surfaces of the bit that may be exposed to reflected laserenergy, reflections, also be non-absorptive, minimally absorptive, andpreferably be polished or made reflective of the laser beam.

An example of such a bit and system to provide the high power laserenergy and mechanical energy are set forth in FIGS. 1A to C, and in FIG.2.

In FIGS. 1A, 1B and 1C there is shown views of an embodiment of a fixedcutter type laser-mechanical bit. Thus, there is provided alaser-mechanical bit 100 having a body section 101 and a bottom section102. The bottom section 102 has mechanical blades 103, 104, 105, 106,107, 108, 109, and 110.

The bit body 101 may have a receiving slot for each mechanical blade.For example, in FIG. 1A receiving slots, 111, 112, 113, are 114 areidentified. Note that with respect to blades, of the type shown asblades 108, 109 and 110, the receiving slots may be joined or partiallyjoined, into a unitary opening. The bit body 101 has side surfaces orareas, e.g., 115 a, 115 b, 117 in which the blade receiving slots areformed. The bit body 101 has surfaces or areas, e.g., 116 a, 116 b forsupporting gauge pads, e.g., 141. The bit body 101 further has surfaces119 a, 119 b, 119 c, 119 d, that in this embodiment are substantiallynormal to the surfaces 115 a, 115 b, 116 a, 116 b, which surfaces 115 a,115 b, have part of the blade receiving slots formed therein. Thesurface 119 a, 119 b, 119 c, 119 d are connected to surfaces 115 a, 115b, 116 a, 116 b by angled surfaces or areas 118 a, 118 b, 118 c, 118 d.

The bit is further provided with beam blades, 120, 121, 122, 123. Inthis embodiment the beam blades are positioned along essentially theentirely of the width of the bit 100 and merge at the end 126 of beampath slot 125 into a unitary structure. The inner surfaces or sides ofthe beam blades form, in part, slot 125. The outer surfaces or sides ofthe beam blades also form a sidewall for the junk slots, e.g., 170.Thus, the beam blades are positioned in both the bit body section 101and the bottom section 102. Other positions and configurations of thebeam blades are contemplated. In the embodiment of FIGS. 1A and 1B thebottom of the beam blades is located at about the same level as thedepth of cut limiters, e.g., 146, that are located on blades 103, 107,i.e. depth of cut blades, and slightly below the bottom of the cutters,e.g., 134. As used herein “bottom” refers to the section of the bit thatis intended to engage or be closest to the bottom of a borehole, and topof the bit refers to the section furthers away from the bottom. Thedistance between the top and the bottom of the bit would be the bitlength, or longitudinal dimension; and the width would be the dimensiontransverse to the length, e.g., the outside diameter of the bit, as usedherein unless specified otherwise.

The longitudinal position of the bottom of the beam blades with respectto the cutters and any depth of cut limiters, e.g., the beam bladesrelative proximity to the bottom of the borehole, may be varied in eachbit design and configuration and will depend upon factors such as thepower of the laser beam, the type of rock or earth being drilled, theflow of and type of fluid used to keep the beam path clear of cuttingsand debris. In general it is preferable that the longitudinalpositioning of the bottoms of the beam blades, any depth of cut limiterblades and the cutter blades all be relatively close, as shown in FIG.1A, although other positions and configurations are envisioned.

A beam path 124 is formed in the bit, and is bordered, in part, by theinner surfaces or sides of the beam blades 120, 121, 122, 123 and theinner ends of blades 103, 105, 107 and 109. In this embodiment the beampath extends through the center axis 161 of the bit and divides the bitinto two separate sections, as more clearly seen in FIG. 1B. Thus, it ispreferable that the structures and their configuration on one side ofthe beam path 124, be similar, and more preferably the same, as thestructures on the other side of the beam path 124, which is the case forthis embodiment. This positioning and configuration is preferred,although other positions and configurations are contemplated. The beampath 124 should be close to, but preferably not touch the beam blades orthe beam blade inner surfaces. When using high power laser energy, andin particular laser energy greater than 5 kW, 10 kW, 20 kW, 40 kW, 80 kWand greater, if the beam path, and, in particular, the laser beam 160,which is propagated along the beam path, contacts a blade it will meltor otherwise remove that section of the blade in the beam path, andpotentially damage the remaining section of the blade, bit, or other bitstructure or component that is struck.

The beam path in this embodiment also serves as a fluid path for afluid, such as air, nitrogen, or a transmissive, or substantiallytransmissive liquid to the laser beam. This fluid is used to keep thelaser beam path clear and also to remove or help remove cuttings fromthe borehole. Configurations, systems and methods for providing andremoving such fluids in laser drilling, and for keeping the beam pathclear, as well as, the removal of cuttings from the borehole, duringlaser drilling are provided in the following US patent applications andUS Patent Application Publications: Publication No. US 2010/0044102,Publication No. US 2010/0044103, Publication No. US 2010/0044104, Ser.No. 12/896,021, Ser. No. 13/211,729, Ser. No. 13/210,581 and Ser. No.13/222,931, the entire disclosures of each of which are incorporatedherein by reference.

The beam blades 120, 121, 122 and 123 form a beam path slot 125, whichslot has ends, e.g., 126 a, 126 b. In this embodiment, although otherconfigurations and positions are contemplated, the beam path slot 125extends from the bottom section 102 partially into the bit body section101. The beam path slot 125 may also have end sections 126 a, 126 b,these end sections 126 a, 126 b, are angled, such that they do notextend into the beam path. The beam pattern, e.g., the shape of the areaof illumination by the laser upon the bottom of the borehole, or at anycross section of the beam as it is traveling toward the area to be cut,e.g., a borehole surface, when the bit is not in rotation, in thisembodiment is preferably a narrow ellipse or rectangular type ofpattern, and more preferably may be such a generally ellipticalrectangular pattern where less energy or on laser energy is provided tocenter of pattern. (In FIG. 1B the laser beam 160 is shown as having abeam pattern that is substantially rectangular.) The beam path for thispattern expands from the optics, not shown, until it strikes the bottomof the borehole (see and compare, FIG. 1C showing a cross section of thelaser beam 160 and the beam path 161, with FIG. 1B showing the bottomview of the laser beam pattern, and thus, the shape of the area ofillumination of the bottom surface of the borehole by the laser beamwhen the beam is not rotating). It should additionally be noted that inthis embodiment the beam path is such that the area of illumination ofthe bottom of the borehole surface is wider, i.e., a larger diameter,than the diameter of the bit, put about the same as the outer diameterof the gauge cutters. It is contemplated that the area of illuminationmay be equal to the bit diameter (excluding or including gauge cuttersand/or gauge reamers as forming the outer diameter of the bit),substantially the same as the bit diameter (excluding or including gaugecutters and/or gauge reamers as forming the outer diameter of the bit),greater than the bit diameter (excluding or including gauge cuttersand/or gauge reamers as forming the outer diameter of the bit). Thebottom of the end section 126 also defines the end of the slot 125 withrespect to the outer surface of the bit body. In this embodiment the endof the slot 125 is at about the same longitudinal position as the end ofthe blades, e.g., 127.

The slot, beam slot or beam path slot refers to the opening or openings,e.g., a slot, in the sides, or side walls, of the bit that permit thebeam path and the laser beam to extend out of, or from the side of thebit, as illustrated, by way of example, in FIG. 1C.

In the embodiment of FIGS. 1A-C there are provided gauge cutters, 128,129, 130, 131. The gauge cutters are located on blades 105, 106, 109 and110. Blades 106 and 110 only support gauge cutters 128, 130. Blades 105,109 support gauge cutters 131, 129, as well as, bottom cutters 132, 133,134, 138, 139, 140, which cutters remove material from the bottom of theborehole, after it has been softened, or otherwise weakened, e.g.,laser-affected material, by the laser beam 160. Depending upon theconfiguration and shape of the laser beam, the gauge cutters may also beremoving laser-affected rock or material. Gauge pads, e.g., 141 arepositioned in surfaces of the bit body, e.g., 116 a. In this embodimentgauge reamers 142, 143, 144, 145 are positioned in blades 104, 105 (andalso similarly positioned in blades 108, 109 although not seen in FIG.1A). Blades 103 and 107 have depth of cut limiters, e.g., 146. Theblades, and in particular the blades having cutters, may have internalpassages for cooling, e.g., vents or ports, such as, e.g., 147, 148, 149(it being noted that the actual openings for vents 148, 149, are notseen in the view of FIG. 1A).

As best illustrated in FIG. 1B, the cutters are positioned with respectto each other, such that they each take a slightly different path alongthe bottom of the borehole, in this way each cutter is assisting in theremoval of laser-affected rock, and preferably does not encounter anyrock that has not first been affected by the laser. In this embodimentthe distance of travel by a cutter before it contacts laser-affectedrock is shown by arc 162. Arc 162 defines an angle between the laserbeam path, and in this embodiment the laser beam, and the plane of theblade supporting the cutters. This angle, which may be referred to asthe “beam path angle,” can be from about 90 degrees to about 140degrees, about 100 degrees to about 130 degrees, and about 110 degreesto about 120 degrees. Beam path angles of less than 90 degrees may beemployed, but are not preferred, as they tend to not give enough timefor the heat deposited by the laser to affect the rock before the cutterreaches the area of laser affected rock. (Greater angles than 140degrees may be employed, however, at greater angles space and strengthof component issues can become significant, as the blades have verylittle space in which to be positioned.) Additionally, when multipleblades are used, each blade could have the same, substantially the same,or a different angle (although care should be taken when using differentangles to make certain that the cutters and overall engagement with theborehole surface is properly balanced.) In the embodiment of FIG. 1Bthis angle, defined by arc 162, is 135 degrees.

This angle between the laser beam (and the beam path, since generally ina properly functioning bit they are coincident) and the cutter positionhas a relationship to, and can be varied and selected to, address andmaximize, efficiency based upon several factors, including for example,the laser power that is delivered to the rock, the reflectivity andabsorptivity of the rock to the laser beam, the rate and depth to whichthe laser beam's energy is transmitted into the rock, the thermalproperties of the rock, the porosity of the rock, and the speed, i.e.,RPM at which the bit is rotated. Thus, as the laser is fired, e.g., alaser beam is propagated, along its beam path from optics to the surfaceof the borehole, a certain amount of time will pass from when the laserfirst contacts a particular area of the surface of the borehole untilthe cutter revolves around and reaches that point. This time can bereferred to as soak time. Depending upon the above factors, the soaktime can be adjusted, and optimized to a certain extent by the selectionof the cutter-laser beam angle.

The bit 100 has channels, e.g., junk slots, 170, 171 that provide aspace between the bit 100 and the wall or side surface 150 of theborehole, for the passage of cuttings up the borehole. The relationshipof the gauge cutters 129, 128, 131, 130 as well as other components ofthe bit 100 to the wall of the borehole 150 can been seen in FIG. 1B.

The blades that support the cutters, 104, 105, 106, 108, 109, 110, i.e.,the cutter blades, in the embodiment of FIGS. 1A-C, are essentiallyright angle shaped. Thus, the bottom section of the blades, i.e., thelower end holding the cutters that engage the bottom and/or gauge of theborehole, and also the associated bottom of the cutters positioned inthat end (e.g., cutters 134,133, 132,129), are along an essentiallystraight line that forms a right angle with the side section of theblades, i.e., the side end holding the cutters that engage the sideand/or gauge of the borehole, and also the associated side of thecutters positioned in that end (e.g., cutters 142, 144, 129) form aright angle. This right angle configuration of all of the cutter blades,as shown in the embodiment of FIG. 1, is referred to as a flat bottomconfiguration, or a flat bottom laser-mechanical bit. Thus, the lowerends of the blades, as well as their associated cutters, are essentiallyco-planar and thus provided the flat bottom of the bottom section 102 ofthe bit 100. Accordingly, in laser mechanical-bits, having fixedcutters, it is preferable that the bottom of the bit, as primarilydefined by the end of the cutter blades, and the position of the cuttersin those ends, is essentially flat and more preferably flat, and as suchwill engage the borehole in an essentially even manner, and morepreferably an even manner, and will in general provide a borehole withan essentially flat bottom and more preferably a flat bottom.

In the bit of FIG. 1 the cutters, e.g., 134, 133, 132, gauge cutters,e.g., 129, and gauge reamers, e.g., 144, 142, may be PDC; and the gaugepads, e.g., 141, may be carbide inserts, which provides for impactresistance, enhanced wear, as well as bit stability.

Further examples of laser-mechanical bits, beam paths, beam patternsincluding split beam patterns, hybrid-laser-mechanical bits, beam pathangles and related processes and systems are disclosed and taught in thefollowing U.S. patent applications Ser. No. 61/446,043 and co-filedpatent application having attorney docket no. 13938/79 (Foro s13a), theentire disclosures of each of which are incorporated herein byreference.

Thus, in general, and by way of example, there is provided in FIG. 2 ahigh efficiency laser drilling system 1000 for creating a borehole 1001in the earth 1002. FIG. 2 provides a cut away perspective view showingthe surface of the earth 1030 and a cut away of the earth 1002 below thesurface 1030. In general and by way of example, there is provided asource of electrical power 1003, which provides electrical power bycables 1004 and 1005 to a laser 1006 and a chiller 1007 for the laser1006. The laser provides a laser beam, i.e., laser energy, that can beconveyed by a laser beam transmission means 1008 to a spool of tubing1009. A source of fluid 1010 is provided. The fluid is conveyed by fluidconveyance means 1011 to the spool of tubing 1009.

The spool of tubing 1009, e.g., coiled tubing, composite tubing or otherconveyance device, is rotated to advance and retract the tubing 1012.Preferred examples of such conveyance means are disclosed and taught inthe following US patent applications and US Patent ApplicationPublications: Publication No. US 2010/0044106, Publication No. US2010/0044104, Publication No. US 2010/0044105, Publication No. US2010/0044103, Publication No. US 2010/0215326, Publication No.2012/0020631, Ser. No. 13/210,581, Ser. No. 13/366,882 and Ser. No.13/211,729, the entire disclosures of each of which are incorporatedherein by reference. Thus, the laser beam transmission means 1008 andthe fluid conveyance means 1011 are attached to the spool of tubing 1009by means of rotating coupling means 1013. The tubing 1012 contains ameans to transmit the laser beam along the entire length of the tubing,i.e., “long distance high power laser beam transmission means,” to thebottom hole assembly, 1014. The tubing 1012 also contains a means toconvey the fluid along the entire length of the tubing 1012 to thebottom hole assembly 1014.

Additionally, there is provided a support structure 1015, which holds aninjector 1016, to facilitate movement of the tubing 1012 in the borehole1001. Further other support structures may be employed, for example,such structures could be derrick, crane, mast, tripod, or other similartype of structure or hybrid and combinations of these. As the boreholeis advance to greater depths from the surface 1030, the use of adiverter 1017, a blow out preventer (BOP) 1018, and a fluid and/orcutting handling system 1019 may become necessary. The tubing 1012 ispassed from the injector 1016 through the diverter 1017, the BOP 1018, awellhead 1020 and into the borehole 1001.

The fluid is conveyed to the bottom 1021 of the borehole 1001. At thatpoint the fluid exits at or near the bottom hole assembly 1014 and isused, among other things, to carry the cuttings, which are created fromadvancing a borehole, back up and out of the borehole. Thus, thediverter 1017 directs the fluid as it returns carrying the cuttings tothe fluid and/or cuttings handling system 1019 through connector 1022.This handling system 1019 is intended to prevent waste products fromescaping into the environment and separates and cleans waste productsand either vents the cleaned fluid to the air, if permissibleenvironmentally and economically, as would be the case if the fluid wasnitrogen, or returns the cleaned fluid to the source of fluid 1010, orotherwise contains the used fluid for later treatment and/or disposal.

The BOP 1018 serves to provide multiple levels of emergency shut offand/or containment of the borehole should a high-pressure event occur inthe borehole, such as a potential blow-out of the well. The BOP isaffixed to the wellhead 1020. The wellhead in turn may be attached tocasing. For the purposes of simplification the structural components ofa borehole such as casing, hangers, and cement are not shown. It isunderstood that these components may be used and will vary based uponthe depth, type, and geology of the borehole, as well as, other factors.

The downhole end 1023 of the tubing 1012 is connected to the bottom holeassembly 1014. The bottom hole assembly 1014 contains optics fordelivering the laser beam 1024 to its intended target, in the case ofFIG. 1, the bottom 1021 of the borehole 1001. The bottom hole assembly1014, for example, also contains means for delivering the fluid.

Thus, in general this system operates to create and/or advance aborehole by having the laser create laser energy in the form of a laserbeam. The laser beam is then transmitted from the laser through thespool and into the tubing. At which point, the laser beam is thentransmitted to the bottom hole assembly where it is directed toward thesurfaces of the earth and/or borehole.

Without being bound by the following theory providing an explanation forthe synergistic effects the present method obtains, and without beingbound by the following theory of energy-rock interaction, physics andthermodynamics, the following theory is offered by way of illustrationand to assist in the understanding of, and explanation for, thesurprising and never before obtained results of these methods.

Thus, this process can be viewed as a hybrid thermal/mechanical processin which thermally-induced compressive stresses are generated in a thinskin of rock at the drilling surface. These thermally induced stressescreate fractures parallel to the surface of the rock and give rise torock removal from the borehole via chips of material. Mechanical cutteraction is present primarily to ensure continuous removal of thefractured material, which in the presence of laser energy only might notbe completely expelled from the surface. The physics of the process andexperimental and theoretical results indicate that higher rates ofpenetration can be achieved by increases in laser power delivered to thedrilling surface.

When laser power is absorbed by a rock, the response depends on both theintensity of the impinging laser power, as well as, the illuminationtime. As shown in the chart of FIG. 3, the material response cangenerally include several regimes, which may be generally classified as:an ultrafast regime 310, a heating regime 320, a melting regime 330, anda vaporization regime 340. Various processes may occur along theseregimes, such as shock hardening 341, drilling 342, glazing 331, cutting332, welding 333, cladding 334, stereo lithography 321, andtransformation hardening 322. At laser intensities and times below themelting of rock, regime 340, lies the regime in which spallation or rockfragmentation occur, as shown in regime area 350. The spallation regime350 is the preferred area in which it is presently believed that thegreatest synergistic benefit for the tailored directed energy mechanicalenergy process may occur.

When laser power is absorbed by the rock, a thin layer of rock near thesurface of the sample is rapidly heated. The thickness of the layer isdetermined both by the quantity of absorbed laser power, and the thermalproperties of the rock. Rock is a naturally insulating material, whichmeans that the propagation of heat into the rock is slow, and the heatedregion may by necessity be very near the surface. In an unconstrainedrock sample, laser absorption would cause the heated region to expand involume. However, in a drilling environment, the heated rock isconstrained on all sides by the surrounding rock mass, and the result isa thermally induced stress state in the heated section that iscompressive in nature.

When the magnitude of the thermally induced stress reaches a levelcomparable to the compressive strength of the rock, it induces fracturein the direction of the maximum compressive stress (i.e., parallel tothe heated surface). Under sufficiently large stress, these fracturescan extend to very long distances until they intersect with the surface,resulting in the formation of chips, in a process known as “spallation”.Turning to FIG. 4, these chips 401, 402, 403, 404 are characterized by ahigh aspect ratio, e.g., the lateral dimensions 1.48″ arrow 411, and1.87″ arrow 412 are much greater than the thickness 0.140″ of chip 404.These chips, e.g., 401 of FIG. 4 are basalt. Similar characteristics ofdolomite chips are shown in FIG. 5. Thus, chips 501, 502, 503, 504, 505,506, 507, 508, 509, 510, and 511 are characterized by a high aspectratio, e.g., the lateral dimensions 1.06″ arrow 521, and 1.52″ arrow522, are much greater than the thickness 0.182″ of chip 511.

However, spallation without a mechanical removal mechanism may be and attime has been shown to be an unreliable drilling solution. Not everyrock type spalls (e.g., a spallable limestone is believed to have neverbeen identified, for example), and macroscopic fractures in the rockmass can inhibit the spallation process. Although the generation ofthermal stress and stress-induced fracture is likely a universal rockresponse, the explosive release of spalled chips is presently believedto be material specific.

The introduction of mechanical action to a primarily thermal process,then, can increase robustness in a synergistic manner by removing thethermally fractured and damaged material without relying on explosivespallation for rock removal. For a combined thermal/mechanical process,a laser represents an ideal directed energy source, as a high flux ofenergy can be delivered to the rock over a precisely controlled areadesigned to minimize heat loads on the mechanical cutters. In thepreferred method of operation the role of the mechanical cutters is toprovide a minimum amount of pressure sufficient to remove the damagedmaterial; and so that they do not otherwise contribute substantially tothe rate of material removal.

The surface temperature of the rock during the process may generally bearound 250-650° C., which is the temperature rise sufficient to generatecompressive stresses comparable to the strength of the rock; broaderranges are provide in the table of examples and may prove advantageousfor various tailored drilling conditions and parameters, Under intenselaser power, the surface temperature rise may be sufficient to melt rockdirectly under the laser beam. This melting would reduce or eliminatethe thermal stresses responsible for laser processing, and is thereforepreferably a condition to be avoided for this method of processing.Processes whereby the rock surface is melted allowed to cool and thenscraped off are contemplated. Such processes do not rely upon aspallation regime and thus may have a broader application to differentmaterials and in particular materials that do not exhibit spallation.Thus, this directed energy mechanical energy process is not materialspecific.

The methods provided herein can further be understood by the exemplaryconditions and parameters set forth in the examples of Table 1. As usedin the Table 1, the headings have the following meanings:

WOB: Weight on bit. Force applied by the bit. Units of pounds.

ROP: Rate of penetration. This is the speed of advancement of thedrilling surface. Units of feet per hour.

RPM: Rotation speed of the bit in revolutions per minute.

Torque: the degree of twist applied by the bit. Units of foot-pounds.

Mechanical power: The power transmitted to the rock by the bit, given bythe equation torque*RPM. Units of kilowatts.

Ratio of DE/ME: The ratio of directed energy or directed laser energy tomechanical energy is the delivered directed laser energy (DE) divided bythe delivered mechanical energy (ME). Dimensionless number.

DE Power/Area: The directed energy laser power per unit of drillingsurface area. Units are Watts per square centimeter.

ME Power/Area: The delivered mechanical energy power per unit ofdrilling surface area. Units are Watts per square centimeter.

TABLE 1 Compressive Sonic Velocity Hole Diameter Example # Rock TypeStrength (ksi) (m/s) Porosity (%) Laser Power (kW) RPM (inches) WOB 1Sandstone 35 4800 3.8% 5 120 3.25 200 2 Sandstone 35 4800 3.8% 5 2403.25 1000 3 Sandstone 35 4800 3.8% 5 360 3.25 200 4 Sandstone 35 48003.8% 5 720 3.25 2000 5 Sandstone 35 4800 3.8% 10 120 3.25 200 6Sandstone 35 4800 3.8% 10 240 3.25 1000 7 Sandstone 35 4800 3.8% 10 3603.25 200 8 Sandstone 35 4800 3.8% 10 720 3.25 2000 9 Sandstone 35 48003.8% 10 1200 3.25 500 10 Sandstone 35 4800 3.8% 15 120 3.25 200 11Sandstone 35 4800 3.8% 15 240 3.25 1000 12 Sandstone 35 4800 3.8% 15 3603.25 200 13 Sandstone 35 4800 3.8% 15 720 3.25 2000 14 Sandstone 35 48003.8% 15 1200 3.25 500 15 Sandstone 35 4800 3.8% 20 120 3.25 200 16Sandstone 35 4800 3.8% 20 240 3.25 1000 17 Sandstone 35 4800 3.8% 20 3603.25 200 18 Sandstone 35 4800 3.8% 20 720 3.25 2000 19 Sandstone 35 48003.8% 20 1200 3.25 500 20 Sandstone 35 4800 3.8% 25 240 3.25 1000 21Sandstone 35 4800 3.8% 25 360 3.25 200 22 Sandstone 35 4800 3.8% 25 7203.25 2000 23 Sandstone 35 4800 3.8% 25 1200 3.25 500 24 Sandstone 354800 3.8% 30 240 3.25 1000 25 Sandstone 35 4800 3.8% 30 360 3.25 200 26Sandstone 35 4800 3.8% 30 720 3.25 2000 27 Sandstone 35 4800 3.8% 301200 3.25 500 28 Sandstone 35 4800 3.8% 10 240 6 1500 29 Sandstone 354800 3.8% 10 360 6 3000 30 Sandstone 35 4800 3.8% 10 720 6 2000 31Sandstone 35 4800 3.8% 10 1200 6 500 32 Sandstone 35 4800 3.8% 20 120 6500 33 Sandstone 35 4800 3.8% 20 240 6 1500 34 Sandstone 35 4800 3.8% 20360 6 3000 35 Sandstone 35 4800 3.8% 20 720 6 2000 36 Sandstone 35 48003.8% 20 1200 6 500 37 Sandstone 35 4800 3.8% 30 120 6 500 38 Sandstone35 4800 3.8% 30 240 6 1500 39 Sandstone 35 4800 3.8% 30 360 6 3000 40Sandstone 35 4800 3.8% 30 720 6 2000 41 Sandstone 35 4800 3.8% 30 1200 6500 42 Sandstone 35 4800 3.8% 40 120 6 500 43 Sandstone 35 4800 3.8% 40240 6 1500 44 Sandstone 35 4800 3.8% 40 360 6 3000 45 Sandstone 35 48003.8% 40 720 6 2000 46 Sandstone 35 4800 3.8% 40 1200 6 500 47 Sandstone35 4800 3.8% 50 120 6 500 48 Sandstone 35 4800 3.8% 50 240 6 1500 49Sandstone 35 4800 3.8% 50 360 6 3000 50 Sandstone 35 4800 3.8% 50 720 62000 51 Sandstone 35 4800 3.8% 50 1200 6 500 52 Sandstone 35 4800 3.8%60 240 6 1500 53 Sandstone 35 4800 3.8% 60 360 6 3000 54 Sandstone 354800 3.8% 60 720 6 2000 55 Sandstone 35 4800 3.8% 60 1200 6 500 56Sandstone 35 4800 3.8% 70 240 6 1500 57 Sandstone 35 4800 3.8% 70 360 63000 58 Sandstone 35 4800 3.8% 70 720 6 2000 59 Sandstone 35 4800 3.8%70 1200 6 500 60 Sandstone 35 4800 3.8% 80 360 6 3000 61 Sandstone 354800 3.8% 80 720 6 2000 62 Sandstone 35 4800 3.8% 80 1200 6 500 63Sandstone 35 4800 3.8% 15 240 8.5 2000 64 Sandstone 35 4800 3.8% 15 3608.5 3500 65 Sandstone 35 4800 3.8% 15 720 8.5 5000 66 Sandstone 35 48003.8% 15 1200 8.5 1000 67 Sandstone 35 4800 3.8% 30 120 8.5 1000 68Sandstone 35 4800 3.8% 30 240 8.5 2000 69 Sandstone 35 4800 3.8% 30 3608.5 3500 70 Sandstone 35 4800 3.8% 30 720 8.5 5000 71 Sandstone 35 48003.8% 45 120 8.5 1000 72 Sandstone 35 4800 3.8% 45 240 8.5 2000 73Sandstone 35 4800 3.8% 45 360 8.5 3500 74 Sandstone 35 4800 3.8% 45 7208.5 5000 75 Sandstone 35 4800 3.8% 45 1200 8.5 1000 76 Sandstone 35 48003.8% 60 120 8.5 1000 77 Sandstone 35 4800 3.8% 60 240 8.5 2000 78Sandstone 35 4800 3.8% 60 360 8.5 3500 79 Sandstone 35 4800 3.8% 60 7208.5 5000 80 Sandstone 35 4800 3.8% 60 1200 8.5 1000 81 Sandstone 35 48003.8% 75 120 8.5 1000 82 Sandstone 35 4800 3.8% 75 240 8.5 2000 83Sandstone 35 4800 3.8% 75 360 8.5 3500 84 Sandstone 35 4800 3.8% 75 7208.5 5000 85 Sandstone 35 4800 3.8% 75 1200 8.5 1000 86 Sandstone 35 48003.8% 90 120 8.5 1000 87 Sandstone 35 4800 3.8% 90 240 8.5 2000 88Sandstone 35 4800 3.8% 90 360 8.5 3500 89 Sandstone 35 4800 3.8% 90 7208.5 5000 90 Sandstone 35 4800 3.8% 90 1200 8.5 1000 91 Sandstone 35 48003.8% 105 120 8.5 1000 92 Sandstone 35 4800 3.8% 105 240 8.5 2000 93Sandstone 35 4800 3.8% 105 360 8.5 3500 94 Sandstone 35 4800 3.8% 105720 8.5 5000 95 Sandstone 35 4800 3.8% 105 1200 8.5 1000 96 Sandstone 354800 3.8% 120 240 8.5 2000 97 Sandstone 35 4800 3.8% 120 360 8.5 3500 98Sandstone 35 4800 3.8% 120 720 8.5 5000 99 Sandstone 35 4800 3.8% 1201200 8.5 1000 100 Dolomite 30 5400 3.2% 5 240 3.25 1000 101 Dolomite 305400 3.2% 5 360 3.25 200 102 Dolomite 30 5400 3.2% 5 720 3.25 2000 103Dolomite 30 5400 3.2% 10 120 3.25 200 104 Dolomite 30 5400 3.2% 10 2403.25 1000 105 Dolomite 30 5400 3.2% 10 360 3.25 200 106 Dolomite 30 54003.2% 10 720 3.25 2000 107 Dolomite 30 5400 3.2% 10 1200 3.25 500 108Dolomite 30 5400 3.2% 15 120 3.25 200 109 Dolomite 30 5400 3.2% 15 2403.25 1000 110 Dolomite 30 5400 3.2% 15 360 3.25 200 111 Dolomite 30 54003.2% 15 720 3.25 2000 112 Dolomite 30 5400 3.2% 15 1200 3.25 500 113Dolomite 30 5400 3.2% 20 120 3.25 200 114 Dolomite 30 5400 3.2% 20 2403.25 1000 115 Dolomite 30 5400 3.2% 20 360 3.25 200 116 Dolomite 30 54003.2% 20 720 3.25 2000 117 Dolomite 30 5400 3.2% 20 1200 3.25 500 118Dolomite 30 5400 3.2% 25 120 3.25 200 119 Dolomite 30 5400 3.2% 25 2403.25 1000 120 Dolomite 30 5400 3.2% 25 360 3.25 200 121 Dolomite 30 54003.2% 25 720 3.25 2000 122 Dolomite 30 5400 3.2% 25 1200 3.25 500 123Dolomite 30 5400 3.2% 30 120 3.25 200 124 Dolomite 30 5400 3.2% 30 2403.25 1000 125 Dolomite 30 5400 3.2% 30 360 3.25 200 126 Dolomite 30 54003.2% 30 720 3.25 2000 127 Dolomite 30 5400 3.2% 30 1200 3.25 500 128Dolomite 30 5400 3.2% 10 240 6 1500 129 Dolomite 30 5400 3.2% 10 360 63000 130 Dolomite 30 5400 3.2% 10 720 6 2000 131 Dolomite 30 5400 3.2%10 1200 6 500 132 Dolomite 30 5400 3.2% 20 120 6 500 133 Dolomite 305400 3.2% 20 240 6 1500 134 Dolomite 30 5400 3.2% 20 360 6 3000 135Dolomite 30 5400 3.2% 20 720 6 2000 136 Dolomite 30 5400 3.2% 20 1200 6500 137 Dolomite 30 5400 3.2% 30 120 6 500 138 Dolomite 30 5400 3.2% 30240 6 1500 139 Dolomite 30 5400 3.2% 30 360 6 3000 140 Dolomite 30 54003.2% 30 720 6 2000 141 Dolomite 30 5400 3.2% 30 1200 6 500 142 Dolomite30 5400 3.2% 40 120 6 500 143 Dolomite 30 5400 3.2% 40 240 6 1500 144Dolomite 30 5400 3.2% 40 360 6 3000 145 Dolomite 30 5400 3.2% 40 720 62000 146 Dolomite 30 5400 3.2% 40 1200 6 500 147 Dolomite 30 5400 3.2%50 120 6 500 148 Dolomite 30 5400 3.2% 50 240 6 1500 149 Dolomite 305400 3.2% 50 360 6 3000 150 Dolomite 30 5400 3.2% 50 720 6 2000 151Dolomite 30 5400 3.2% 50 1200 6 500 152 Dolomite 30 5400 3.2% 60 120 6500 153 Dolomite 30 5400 3.2% 60 240 6 1500 154 Dolomite 30 5400 3.2% 60360 6 3000 155 Dolomite 30 5400 3.2% 60 720 6 2000 156 Dolomite 30 54003.2% 60 1200 6 500 157 Dolomite 30 5400 3.2% 70 120 6 500 158 Dolomite30 5400 3.2% 70 240 6 1500 159 Dolomite 30 5400 3.2% 70 360 6 3000 160Dolomite 30 5400 3.2% 70 720 6 2000 161 Dolomite 30 5400 3.2% 70 1200 6500 162 Dolomite 30 5400 3.2% 80 120 6 500 163 Dolomite 30 5400 3.2% 80240 6 1500 164 Dolomite 30 5400 3.2% 80 360 6 3000 165 Dolomite 30 54003.2% 80 720 6 2000 166 Dolomite 30 5400 3.2% 80 1200 6 500 167 Dolomite30 5400 3.2% 15 120 8.5 1000 168 Dolomite 30 5400 3.2% 15 240 8.5 2000169 Dolomite 30 5400 3.2% 15 360 8.5 3500 170 Dolomite 30 5400 3.2% 15720 8.5 5000 171 Dolomite 30 5400 3.2% 15 1200 8.5 1000 172 Dolomite 305400 3.2% 30 120 8.5 1000 173 Dolomite 30 5400 3.2% 30 240 8.5 2000 174Dolomite 30 5400 3.2% 30 360 8.5 3500 175 Dolomite 30 5400 3.2% 30 7208.5 5000 176 Dolomite 30 5400 3.2% 45 120 8.5 1000 177 Dolomite 30 54003.2% 45 240 8.5 2000 178 Dolomite 30 5400 3.2% 45 360 8.5 3500 179Dolomite 30 5400 3.2% 45 720 8.5 5000 180 Dolomite 30 5400 3.2% 60 1208.5 1000 181 Dolomite 30 5400 3.2% 60 240 8.5 2000 182 Dolomite 30 54003.2% 60 360 8.5 3500 183 Dolomite 30 5400 3.2% 60 720 8.5 5000 184Dolomite 30 5400 3.2% 75 120 8.5 1000 185 Dolomite 30 5400 3.2% 75 2408.5 2000 186 Dolomite 30 5400 3.2% 75 360 8.5 3500 187 Dolomite 30 54003.2% 75 720 8.5 5000 188 Dolomite 30 5400 3.2% 75 1200 8.5 1000 189Dolomite 30 5400 3.2% 90 120 8.5 1000 190 Dolomite 30 5400 3.2% 90 2408.5 2000 191 Dolomite 30 5400 3.2% 90 360 8.5 3500 192 Dolomite 30 54003.2% 90 720 8.5 5000 193 Dolomite 30 5400 3.2% 90 1200 8.5 1000 194Dolomite 30 5400 3.2% 105 120 8.5 1000 195 Dolomite 30 5400 3.2% 105 2408.5 2000 196 Dolomite 30 5400 3.2% 105 360 8.5 3500 197 Dolomite 30 54003.2% 105 720 8.5 5000 198 Dolomite 30 5400 3.2% 105 1200 8.5 1000 199Dolomite 30 5400 3.2% 120 120 8.5 1000 200 Dolomite 30 5400 3.2% 120 2408.5 2000 201 Dolomite 30 5400 3.2% 120 360 8.5 3500 202 Dolomite 30 54003.2% 120 720 8.5 5000 203 Dolomite 30 5400 3.2% 120 1200 8.5 1000 204Granite 20 4700 1.5% 5 240 3.25 1000 205 Granite 20 4700 1.5% 5 360 3.25200 206 Granite 20 4700 1.5% 5 720 3.25 2000 207 Granite 20 4700 1.5% 51200 3.25 500 208 Granite 20 4700 1.5% 10 120 3.25 200 209 Granite 204700 1.5% 10 240 3.25 1000 210 Granite 20 4700 1.5% 10 360 3.25 200 211Granite 20 4700 1.5% 10 720 3.25 2000 212 Granite 20 4700 1.5% 15 2403.25 1000 213 Granite 20 4700 1.5% 15 360 3.25 200 214 Granite 20 47001.5% 15 720 3.25 2000 215 Granite 20 4700 1.5% 20 720 3.25 2000 216Granite 20 4700 1.5% 25 720 3.25 2000 217 Granite 20 4700 1.5% 25 12003.25 500 218 Granite 20 4700 1.5% 30 720 3.25 2000 219 Granite 20 47001.5% 30 1200 3.25 500 220 Granite 20 4700 1.5% 10 120 6 500 221 Granite20 4700 1.5% 10 240 6 1500 222 Granite 20 4700 1.5% 10 360 6 3000 223Granite 20 4700 1.5% 10 720 6 2000 224 Granite 20 4700 1.5% 20 120 6 500225 Granite 20 4700 1.5% 20 240 6 1500 226 Granite 20 4700 1.5% 20 360 63000 227 Granite 20 4700 1.5% 20 720 6 2000 228 Granite 20 4700 1.5% 201200 6 500 229 Granite 20 4700 1.5% 30 240 6 1500 230 Granite 20 47001.5% 30 360 6 3000 231 Granite 20 4700 1.5% 30 720 6 2000 232 Granite 204700 1.5% 30 1200 6 500 233 Granite 20 4700 1.5% 40 240 6 1500 234Granite 20 4700 1.5% 40 360 6 3000 235 Granite 20 4700 1.5% 40 720 62000 236 Granite 20 4700 1.5% 40 1200 6 500 237 Granite 20 4700 1.5% 50360 6 3000 238 Granite 20 4700 1.5% 50 720 6 2000 239 Granite 20 47001.5% 50 1200 6 500 240 Granite 20 4700 1.5% 60 720 6 2000 241 Granite 204700 1.5% 60 1200 6 500 242 Granite 20 4700 1.5% 70 720 6 2000 243Granite 20 4700 1.5% 70 1200 6 500 244 Granite 20 4700 1.5% 80 1200 6500 245 Granite 20 4700 1.5% 15 120 8.5 1000 246 Granite 20 4700 1.5% 15240 8.5 2000 247 Granite 20 4700 1.5% 15 360 8.5 3500 248 Granite 204700 1.5% 15 720 8.5 5000 249 Granite 20 4700 1.5% 30 120 8.5 1000 250Granite 20 4700 1.5% 30 240 8.5 2000 251 Granite 20 4700 1.5% 30 360 8.53500 252 Granite 20 4700 1.5% 30 720 8.5 5000 253 Granite 20 4700 1.5%30 1200 8.5 1000 254 Granite 20 4700 1.5% 45 120 8.5 1000 255 Granite 204700 1.5% 45 240 8.5 2000 256 Granite 20 4700 1.5% 45 360 8.5 3500 257Granite 20 4700 1.5% 45 720 8.5 5000 258 Granite 20 4700 1.5% 45 12008.5 1000 259 Granite 20 4700 1.5% 60 240 8.5 2000 260 Granite 20 47001.5% 60 360 8.5 3500 261 Granite 20 4700 1.5% 60 720 8.5 5000 262Granite 20 4700 1.5% 75 240 8.5 2000 263 Granite 20 4700 1.5% 75 360 8.53500 264 Granite 20 4700 1.5% 75 720 8.5 5000 265 Granite 20 4700 1.5%90 360 8.5 3500 266 Granite 20 4700 1.5% 90 720 8.5 5000 267 Granite 204700 1.5% 105 720 8.5 5000 268 Granite 20 4700 1.5% 120 720 8.5 5000 269Basalt 40 5100 2.1% 5 120 3.25 200 270 Basalt 40 5100 2.1% 5 240 3.251000 271 Basalt 40 5100 2.1% 5 360 3.25 200 272 Basalt 40 5100 2.1% 5720 3.25 2000 273 Basalt 40 5100 2.1% 10 240 3.25 1000 274 Basalt 405100 2.1% 10 360 3.25 200 275 Basalt 40 5100 2.1% 10 720 3.25 2000 276Basalt 40 5100 2.1% 10 1200 3.25 500 277 Basalt 40 5100 2.1% 15 720 3.252000 278 Basalt 40 5100 2.1% 15 1200 3.25 500 279 Basalt 40 5100 2.1% 20720 3.25 2000 280 Basalt 40 5100 2.1% 20 1200 3.25 500 281 Basalt 405100 2.1% 10 240 6 1500 282 Basalt 40 5100 2.1% 10 360 6 3000 283 Basalt40 5100 2.1% 10 720 6 2000 284 Basalt 40 5100 2.1% 10 1200 6 500 285Basalt 40 5100 2.1% 20 240 6 1500 286 Basalt 40 5100 2.1% 20 360 6 3000287 Basalt 40 5100 2.1% 20 720 6 2000 288 Basalt 40 5100 2.1% 20 1200 6500 289 Basalt 40 5100 2.1% 30 360 6 3000 290 Basalt 40 5100 2.1% 30 7206 2000 291 Basalt 40 5100 2.1% 30 1200 6 500 292 Basalt 40 5100 2.1% 40720 6 2000 293 Basalt 40 5100 2.1% 40 1200 6 500 294 Basalt 40 5100 2.1%50 1200 6 500 295 Basalt 40 5100 2.1% 15 120 8.5 1000 296 Basalt 40 51002.1% 15 240 8.5 2000 297 Basalt 40 5100 2.1% 15 360 8.5 3500 298 Basalt40 5100 2.1% 15 720 8.5 5000 299 Basalt 40 5100 2.1% 15 1200 8.5 1000300 Basalt 40 5100 2.1% 30 120 8.5 1000 301 Basalt 40 5100 2.1% 30 2408.5 2000 302 Basalt 40 5100 2.1% 30 360 8.5 3500 303 Basalt 40 5100 2.1%30 720 8.5 5000 304 Basalt 40 5100 2.1% 45 240 8.5 2000 305 Basalt 405100 2.1% 45 360 8.5 3500 306 Basalt 40 5100 2.1% 45 720 8.5 5000 307Basalt 40 5100 2.1% 45 1200 8.5 1000 308 Basalt 40 5100 2.1% 60 360 8.53500 309 Basalt 40 5100 2.1% 60 720 8.5 5000 310 Basalt 40 5100 2.1% 601200 8.5 1000 311 Basalt 40 5100 2.1% 75 720 8.5 5000 312 Basalt 40 51002.1% 75 1200 8.5 1000 313 Basalt 40 5100 2.1% 90 720 8.5 5000 314 Basalt40 5100 2.1% 90 1200 8.5 1000 315 Basalt 40 5100 2.1% 105 1200 8.5 1000Surface Temp. Mechanical DE Power/Area ME Power/Area Example # ROP(ft/hr) Rise (DegC.) Torque (ft-lbs) Power (kW) Ratio of DE/ME(W/cm{circumflex over ( )}2) (W/cm{circumflex over ( )}2) 1 5.5 434 13.10.22 22.3 93.4 4.2 2 6.6 341 65.7 2.24 2.2 93.4 41.8 3 5.7 341 13.1 0.677.4 93.4 12.6 4 15.9 170 131.4 13.44 0.4 93.4 251.0 5 10.6 651 13.1 0.2244.7 186.8 4.2 6 12.4 504 65.7 2.24 4.5 186.8 41.8 7 11.7 467 13.1 0.6714.9 186.8 12.6 8 19.4 308 131.4 13.44 0.7 186.8 251.0 9 13.1 338 32.95.60 1.8 186.8 104.6 10 14.5 866 13.1 0.22 67.0 280.3 4.2 11 17.1 66065.7 2.24 6.7 280.3 41.8 12 16.8 592 13.1 0.67 22.3 280.3 12.6 13 24.4416 131.4 13.44 1.1 280.3 251.0 14 19.2 410 32.9 5.60 2.7 280.3 104.6 1517.5 1081 13.1 0.22 89.3 373.7 4.2 16 20.9 814 65.7 2.24 8.9 373.7 41.817 21.2 717 13.1 0.67 29.8 373.7 12.6 18 29.1 514 131.4 13.44 1.5 373.7251.0 19 24.9 481 32.9 5.60 3.6 373.7 104.6 20 24.0 968 65.7 2.24 11.2467.1 41.8 21 24.9 841 13.1 0.67 37.2 467.1 12.6 22 33.4 608 131.4 13.441.9 467.1 251.0 23 30.0 550 32.9 5.60 4.5 467.1 104.6 24 26.6 1121 65.72.24 13.4 560.5 41.8 25 28.1 965 13.1 0.67 44.7 560.5 12.6 26 37.2 700131.4 13.44 2.2 560.5 251.0 27 34.8 619 32.9 5.60 5.4 560.5 104.6 28 3.7311 182.0 6.20 1.6 54.8 34.0 29 6.5 217 364.0 18.60 0.5 54.8 102.0 305.6 204 242.6 24.80 0.4 54.8 136.0 31 3.4 257 60.7 10.34 1.0 54.8 56.732 6.6 575 60.7 1.03 19.4 109.6 5.7 33 7.4 451 182.0 6.20 3.2 109.6 34.034 9.7 362 364.0 18.60 1.1 109.6 102.0 35 9.2 312 242.6 24.80 0.8 109.6136.0 36 7.2 322 60.7 10.34 1.9 109.6 56.7 37 9.6 754 60.7 1.03 29.0164.5 5.7 38 10.8 582 182.0 6.20 4.8 164.5 34.0 39 13.1 480 364.0 18.601.6 164.5 102.0 40 12.9 398 242.6 24.80 1.2 164.5 136.0 41 11.0 381 60.710.34 2.9 164.5 56.7 42 12.2 933 60.7 1.03 38.7 219.3 5.7 43 13.8 711182.0 6.20 6.5 219.3 34.0 44 16.3 591 364.0 18.60 2.2 219.3 102.0 4516.4 478 242.6 24.80 1.6 219.3 136.0 46 14.6 439 60.7 10.34 3.9 219.356.7 47 14.3 1112 60.7 1.03 48.4 274.1 5.7 48 16.5 839 182.0 6.20 8.1274.1 34.0 49 19.2 699 364.0 18.60 2.7 274.1 102.0 50 19.8 555 242.624.80 2.0 274.1 136.0 51 18.1 497 60.7 10.34 4.8 274.1 56.7 52 18.9 966182.0 6.20 9.7 328.9 34.0 53 21.8 805 364.0 18.60 3.2 328.9 102.0 5422.9 630 242.6 24.80 2.4 328.9 136.0 55 21.5 554 60.7 10.34 5.8 328.956.7 56 21.0 1093 182.0 6.20 11.3 383.7 34.0 57 24.2 910 364.0 18.60 3.8383.7 102.0 58 25.8 705 242.6 24.80 2.8 383.7 136.0 59 24.7 611 60.710.34 6.8 383.7 56.7 60 26.3 1015 364.0 18.60 4.3 438.6 102.0 61 28.5780 242.6 24.80 3.2 438.6 136.0 62 27.8 668 60.7 10.34 7.7 438.6 56.7 632.7 274 343.8 11.71 1.3 41.0 32.0 64 4.5 195 601.6 30.75 0.5 41.0 84.065 14.6 94 859.4 87.85 0.2 41.0 240.0 66 2.6 224 171.9 29.28 0.5 41.080.0 67 4.9 481 171.9 2.93 10.2 81.9 8.0 68 5.5 385 343.8 11.71 2.6 81.932.0 69 7.0 313 601.6 30.75 1.0 81.9 84.0 70 14.5 188 859.4 87.85 0.381.9 240.0 71 7.4 616 171.9 2.93 15.4 122.9 8.0 72 8.2 485 343.8 11.713.8 122.9 32.0 73 9.7 405 601.6 30.75 1.5 122.9 84.0 74 15.5 274 859.487.85 0.5 122.9 240.0 75 8.4 330 171.9 29.28 1.5 122.9 80.0 76 9.6 750171.9 2.93 20.5 163.9 8.0 77 10.7 582 343.8 11.71 5.1 163.9 32.0 78 12.3490 601.6 30.75 2.0 163.9 84.0 79 17.4 349 859.4 87.85 0.7 163.9 240.080 11.2 375 171.9 29.28 2.0 163.9 80.0 81 11.6 884 171.9 2.93 25.6 204.98.0 82 13.0 678 343.8 11.71 6.4 204.9 32.0 83 14.7 572 601.6 30.75 2.4204.9 84.0 84 19.6 416 859.4 87.85 0.9 204.9 240.0 85 14.0 419 171.929.28 2.6 204.9 80.0 86 13.3 1018 171.9 2.93 30.7 245.8 8.0 87 15.1 774343.8 11.71 7.7 245.8 32.0 88 17.0 652 601.6 30.75 2.9 245.8 84.0 8921.9 479 859.4 87.85 1.0 245.8 240.0 90 16.7 463 171.9 29.28 3.1 245.880.0 91 14.9 1152 171.9 2.93 35.9 286.8 8.0 92 17.0 869 343.8 11.71 9.0286.8 32.0 93 19.1 731 601.6 30.75 3.4 286.8 84.0 94 24.2 539 859.487.85 1.2 286.8 240.0 95 19.3 506 171.9 29.28 3.6 286.8 80.0 96 18.8 964343.8 11.71 10.2 327.8 32.0 97 21.1 810 601.6 30.75 3.9 327.8 84.0 9826.3 598 859.4 87.85 1.4 327.8 240.0 99 21.8 549 171.9 29.28 4.1 327.880.0 100 5.1 207 65.7 2.24 2.2 93.4 41.8 101 4.1 218 13.1 0.67 7.4 93.412.6 102 21.7 79 131.4 13.44 0.4 93.4 251.0 103 7.7 406 13.1 0.22 44.7186.8 4.2 104 9.2 310 65.7 2.24 4.5 186.8 41.8 105 8.3 295 13.1 0.6714.9 186.8 12.6 106 21.6 159 131.4 13.44 0.7 186.8 251.0 107 9.7 21132.9 5.60 1.8 186.8 104.6 108 10.6 536 13.1 0.22 67.0 280.3 4.2 109 12.7406 65.7 2.24 6.7 280.3 41.8 110 12.1 371 13.1 0.67 22.3 280.3 12.6 11122.9 232 131.4 13.44 1.1 280.3 251.0 112 14.1 256 32.9 5.60 2.7 280.3104.6 113 12.9 666 13.1 0.22 89.3 373.7 4.2 114 15.6 500 65.7 2.24 8.9373.7 41.8 115 15.4 446 13.1 0.67 29.8 373.7 12.6 116 25.4 298 131.413.44 1.5 373.7 251.0 117 18.3 300 32.9 5.60 3.6 373.7 104.6 118 14.7796 13.1 0.22 111.6 467.1 4.2 119 18.0 593 65.7 2.24 11.2 467.1 41.8 12018.2 521 13.1 0.67 37.2 467.1 12.6 121 28.0 358 131.4 13.44 1.9 467.1251.0 122 22.1 342 32.9 5.60 4.5 467.1 104.6 123 16.2 926 13.1 0.22134.0 560.5 4.2 124 20.0 686 65.7 2.24 13.4 560.5 41.8 125 20.7 596 13.10.67 44.7 560.5 12.6 126 30.5 416 131.4 13.44 2.2 560.5 251.0 127 25.6384 32.9 5.60 5.4 560.5 104.6 128 2.9 187 182.0 6.20 1.6 54.8 34.0 1298.2 106 364.0 18.60 0.5 54.8 102.0 130 6.4 100 242.6 24.80 0.4 54.8136.0 131 2.5 161 60.7 10.34 1.0 54.8 56.7 132 4.7 359 60.7 1.03 19.4109.6 5.7 133 5.5 278 182.0 6.20 3.2 109.6 34.0 134 9.0 203 364.0 18.601.1 109.6 102.0 135 8.0 179 242.6 24.80 0.8 109.6 136.0 136 5.2 203 60.710.34 1.9 109.6 56.7 137 6.9 468 60.7 1.03 29.0 164.5 5.7 138 8.0 359182.0 6.20 4.8 164.5 34.0 139 11.0 282 364.0 18.60 1.6 164.5 102.0 14010.4 237 242.6 24.80 1.2 164.5 136.0 141 7.9 240 60.7 10.34 2.9 164.556.7 142 8.8 577 60.7 1.03 38.7 219.3 5.7 143 10.2 438 182.0 6.20 6.5219.3 34.0 144 13.1 353 364.0 18.60 2.2 219.3 102.0 145 12.9 288 242.624.80 1.6 219.3 136.0 146 10.5 276 60.7 10.34 3.9 219.3 56.7 147 10.5685 60.7 1.03 48.4 274.1 5.7 148 12.2 516 182.0 6.20 8.1 274.1 34.0 14915.2 420 364.0 18.60 2.7 274.1 102.0 150 15.3 337 242.6 24.80 2.0 274.1136.0 151 13.1 311 60.7 10.34 4.8 274.1 56.7 152 11.9 792 60.7 1.03 58.1328.9 5.7 153 14.0 593 182.0 6.20 9.7 328.9 34.0 154 17.0 486 364.018.60 3.2 328.9 102.0 155 17.5 384 242.6 24.80 2.4 328.9 136.0 156 15.5346 60.7 10.34 5.8 328.9 56.7 157 13.1 900 60.7 1.03 67.7 383.7 5.7 15815.6 670 182.0 6.20 11.3 383.7 34.0 159 18.8 551 364.0 18.60 3.8 383.7102.0 160 19.6 430 242.6 24.80 2.8 383.7 136.0 161 17.9 381 60.7 10.346.8 383.7 56.7 162 14.2 1008 60.7 1.03 77.4 438.6 5.7 163 17.1 747 182.06.20 12.9 438.6 34.0 164 20.3 615 364.0 18.60 4.3 438.6 102.0 165 21.6476 242.6 24.80 3.2 438.6 136.0 166 20.1 415 60.7 10.34 7.7 438.6 56.7167 1.5 215 171.9 2.93 5.1 41.0 8.0 168 2.2 162 343.8 11.71 1.3 41.032.0 169 5.5 94 601.6 30.75 0.5 41.0 84.0 170 19.7 46 859.4 87.85 0.241.0 240.0 171 2.1 133 171.9 29.28 0.5 41.0 80.0 172 3.5 301 171.9 2.9310.2 81.9 8.0 173 4.1 236 343.8 11.71 2.6 81.9 32.0 174 6.3 176 601.630.75 1.0 81.9 84.0 175 19.8 92 859.4 87.85 0.3 81.9 240.0 176 5.3 384171.9 2.93 15.4 122.9 8.0 177 6.1 299 343.8 11.71 3.8 122.9 32.0 178 8.0239 601.6 30.75 1.5 122.9 84.0 179 19.7 138 859.4 87.85 0.5 122.9 240.0180 7.0 465 171.9 2.93 20.5 163.9 8.0 181 7.9 359 343.8 11.71 5.1 163.932.0 182 9.8 294 601.6 30.75 2.0 163.9 84.0 183 19.7 183 859.4 87.85 0.7163.9 240.0 184 8.4 546 171.9 2.93 25.6 204.9 8.0 185 9.6 418 343.811.71 6.4 204.9 32.0 186 11.5 345 601.6 30.75 2.4 204.9 84.0 187 20.1228 859.4 87.85 0.9 204.9 240.0 188 10.2 262 171.9 29.28 2.6 204.9 80.0189 9.7 627 171.9 2.93 30.7 245.8 8.0 190 11.2 476 343.8 11.71 7.7 245.832.0 191 13.2 395 601.6 30.75 2.9 245.8 84.0 192 20.9 270 859.4 87.851.0 245.8 240.0 193 12.1 289 171.9 29.28 3.1 245.8 80.0 194 10.9 708171.9 2.93 35.9 286.8 8.0 195 12.6 534 343.8 11.71 9.0 286.8 32.0 19614.7 444 601.6 30.75 3.4 286.8 84.0 197 21.9 310 859.4 87.85 1.2 286.8240.0 198 14.0 316 171.9 29.28 3.6 286.8 80.0 199 11.9 789 171.9 2.9341.0 327.8 8.0 200 13.9 592 343.8 11.71 10.2 327.8 32.0 201 16.1 493601.6 30.75 3.9 327.8 84.0 202 23.1 348 859.4 87.85 1.4 327.8 240.0 20315.8 342 171.9 29.28 4.1 327.8 80.0 204 7.3 481 65.7 2.24 2.2 93.4 41.8205 5.2 507 13.1 0.67 7.4 93.4 12.6 206 47.9 177 131.4 13.44 0.4 93.4251.0 207 7.4 331 32.9 5.60 0.9 93.4 104.6 208 8.7 1097 13.1 0.22 44.7186.8 4.2 209 11.5 800 65.7 2.24 4.5 186.8 41.8 210 10.2 748 13.1 0.6714.9 186.8 12.6 211 48.4 354 131.4 13.44 0.7 186.8 251.0 212 14.7 109965.7 2.24 6.7 280.3 41.8 213 14.0 985 13.1 0.67 22.3 280.3 12.6 214 48.7530 131.4 13.44 1.1 280.3 251.0 215 48.8 706 131.4 13.44 1.5 373.7 251.0216 48.8 883 131.4 13.44 1.9 467.1 251.0 217 26.2 898 32.9 5.60 4.5467.1 104.6 218 48.7 1060 131.4 13.44 2.2 560.5 251.0 219 29.5 1030 32.95.60 5.4 560.5 104.6 220 2.8 606 60.7 1.03 9.7 54.8 5.7 221 4.4 423182.0 6.20 1.6 54.8 34.0 222 18.5 232 364.0 18.60 0.5 54.8 102.0 22314.3 197 242.6 24.80 0.4 54.8 136.0 224 5.7 951 60.7 1.03 19.4 109.6 5.7225 7.4 701 182.0 6.20 3.2 109.6 34.0 226 18.4 464 364.0 18.60 1.1 109.6102.0 227 14.4 393 242.6 24.80 0.8 109.6 136.0 228 7.0 465 60.7 10.341.9 109.6 56.7 229 10.0 953 182.0 6.20 4.8 164.5 34.0 230 18.5 695 364.018.60 1.6 164.5 102.0 231 15.9 570 242.6 24.80 1.2 164.5 136.0 232 10.3580 60.7 10.34 2.9 164.5 56.7 233 12.2 1199 182.0 6.20 6.5 219.3 34.0234 19.2 917 364.0 18.60 2.2 219.3 102.0 235 18.1 730 242.6 24.80 1.6219.3 136.0 236 13.4 692 60.7 10.34 3.9 219.3 56.7 237 20.4 1130 364.018.60 2.7 274.1 102.0 238 20.3 882 242.6 24.80 2.0 274.1 136.0 239 16.3801 60.7 10.34 4.8 274.1 56.7 240 22.3 1029 242.6 24.80 2.4 328.9 136.0241 19.0 910 60.7 10.34 5.8 328.9 56.7 242 24.2 1173 242.6 24.80 2.8383.7 136.0 243 21.5 1019 60.7 10.34 6.8 383.7 56.7 244 23.8 1127 60.710.34 7.7 438.6 56.7 245 2.1 503 171.9 2.93 5.1 41.0 8.0 246 3.5 347343.8 11.71 1.3 41.0 32.0 247 12.6 193 601.6 30.75 0.5 41.0 84.0 24843.5 110 859.4 87.85 0.2 41.0 240.0 249 4.5 770 171.9 2.93 10.2 81.9 8.0250 5.7 573 343.8 11.71 2.6 81.9 32.0 251 12.5 387 601.6 30.75 1.0 81.984.0 252 43.9 219 859.4 87.85 0.3 81.9 240.0 253 5.8 381 171.9 29.28 1.081.9 80.0 254 6.5 1028 171.9 2.93 15.4 122.9 8.0 255 7.9 767 343.8 11.713.8 122.9 32.0 256 13.0 573 601.6 30.75 1.5 122.9 84.0 257 44.1 328859.4 87.85 0.5 122.9 240.0 258 8.4 477 171.9 29.28 1.5 122.9 80.0 2599.9 955 343.8 11.71 5.1 163.9 32.0 260 14.2 744 601.6 30.75 2.0 163.984.0 261 44.3 437 859.4 87.85 0.7 163.9 240.0 262 11.6 1138 343.8 11.716.4 204.9 32.0 263 15.6 906 601.6 30.75 2.4 204.9 84.0 264 44.5 546859.4 87.85 0.9 204.9 240.0 265 17.0 1062 601.6 30.75 2.9 245.8 84.0 26644.6 655 859.4 87.85 1.0 245.8 240.0 267 44.6 764 859.4 87.85 1.2 286.8240.0 268 44.6 874 859.4 87.85 1.4 327.8 240.0 269 4.0 1122 13.1 0.2222.3 93.4 4.2 270 4.8 868 65.7 2.24 2.2 93.4 41.8 271 4.2 849 13.1 0.677.4 93.4 12.6 272 12.1 432 131.4 13.44 0.4 93.4 251.0 273 8.8 1339 65.72.24 4.5 186.8 41.8 274 8.4 1219 13.1 0.67 14.9 186.8 12.6 275 14.3 803131.4 13.44 0.7 186.8 251.0 276 9.7 851 32.9 5.60 1.8 186.8 104.6 27717.6 1107 131.4 13.44 1.1 280.3 251.0 278 14.1 1061 32.9 5.60 2.7 280.3104.6 279 20.6 1388 131.4 13.44 1.5 373.7 251.0 280 17.9 1265 32.9 5.603.6 373.7 104.6 281 2.7 782 182.0 6.20 1.6 54.8 34.0 282 4.9 549 364.018.60 0.5 54.8 102.0 283 4.2 501 242.6 24.80 0.4 54.8 136.0 284 2.4 61360.7 10.34 1.0 54.8 56.7 285 5.4 1185 182.0 6.20 3.2 109.6 34.0 286 7.1949 364.0 18.60 1.1 109.6 102.0 287 6.8 798 242.6 24.80 0.8 109.6 136.0288 5.3 798 60.7 10.34 1.9 109.6 56.7 289 9.5 1286 364.0 18.60 1.6 164.5102.0 290 9.5 1041 242.6 24.80 1.2 164.5 136.0 291 8.1 971 60.7 10.342.9 164.5 56.7 292 12.0 1270 242.6 24.80 1.6 219.3 136.0 293 10.8 114160.7 10.34 3.9 219.3 56.7 294 13.3 1309 60.7 10.34 4.8 274.1 56.7 2951.5 856 171.9 2.93 5.1 41.0 8.0 296 1.9 674 343.8 11.71 1.3 41.0 32.0297 3.4 482 601.6 30.75 0.5 41.0 84.0 298 11.1 244 859.4 87.85 0.2 41.0240.0 299 1.9 527 171.9 29.28 0.5 41.0 80.0 300 3.5 1262 171.9 2.93 10.281.9 8.0 301 4.0 991 343.8 11.71 2.6 81.9 32.0 302 5.1 805 601.6 30.751.0 81.9 84.0 303 11.1 488 859.4 87.85 0.3 81.9 240.0 304 5.9 1282 343.811.71 3.8 122.9 32.0 305 7.1 1065 601.6 30.75 1.5 122.9 84.0 306 11.7719 859.4 87.85 0.5 122.9 240.0 307 6.2 826 171.9 29.28 1.5 122.9 80.0308 8.9 1309 601.6 30.75 2.0 163.9 84.0 309 12.9 924 859.4 87.85 0.7163.9 240.0 310 8.3 957 171.9 29.28 2.0 163.9 80.0 311 14.4 1112 859.487.85 0.9 204.9 240.0 312 10.3 1086 171.9 29.28 2.6 204.9 80.0 313 15.91292 859.4 87.85 1.0 245.8 240.0 314 12.2 1213 171.9 29.28 3.1 245.880.0 315 14.1 1339 171.9 29.28 3.6 286.8 80.0

In these examples of drilling conditions and parameters, the laser poweris to be delivered to the rock surface. The examples are for use withair as the fluid for drilling, and may be utilized with, by way ofexample, the bits and systems that are described in FIGS. 1A-C and 2 ofthis specification and with the bits and systems disclosed and taught inU.S. patent applications Ser. No. 61/446,043 and co-filed patentapplication having attorney docket no. 13938/79 (Foro s13a).

Thus, from the forgoing examples, which provide various illustrativelaser-mechanical drilling conditions and parameters, there iscontemplated generally, and by way of further example, a method oflaser-mechanical drilling a borehole in a formation having at least 500feet, at least about 1,000 ft, at least about 5,000 and at least about10,000 feet of material having a hardness greater than about 15 ksi,greater than about 20 ksi, greater than about 30 ksi, and greater thanabout 40 ksi and at drilling rates, e.g., ROP, of at least about 10ft/hr, at least about 20 ft/hr, at least about 30 ft/hr and at leastabout 40 ft/hr. Such methods in generally would include, by way ofexample, drilling under the following conditions and parameters: (i) anRPM of from about 240 to about 720, a WOB of less than about 2,000 lbs,a DE Power/Area of about 90 W/cm² to about 560 W/cm², and an MEPower/Area of about 4 W/cm² to about 250 W/cm²; (ii) an RPM of fromabout 600 to about 800, a WOB of less than about 5,000 lbs, a DEPower/Area of about 40 W/cm² to about 250 W/cm², and an ME Power/Area ofabout 200 W/cm² to about 3000 W/cm²; (iii) an RPM of from about 600 toabout 1250, a WOB of from about 500 to about 5,000 lbs, a DE Power/Areaof about 90 W/cm² to about 570 W/cm², and an ME Power/Area of about 40W/cm² to about 270 W/cm²; (iv) an RPM of about 250, a WOB of from about1,000 lbs, a DE Power/Area of about 370 W/cm², and an ME Power/Area ofabout 40 W/cm²; (v) an RPM of from about 720, a WOB of from about 2,000lbs, a DE Power/Area of about 190 W/cm², and an ME Power/Area of about250 W/cm²; (vi) an RPM of from about 720, a WOB of from about 2,000 lbs,a DE Power/Area of about 370 W/cm², and an ME Power/Area of about 250W/cm²; (vii) an RPM of from about 720, a WOB of from about 5,000 lbs, aDE Power/Area of about 290 W/cm², and an ME Power/Area of about 240W/cm²; (viii) an RPM of from about 1,200, a WOB of from about 500 lbs, aDE Power/Area of about 470 W/cm², and an ME Power/Area of about 100W/cm²; (ix) an RPM of from about 720, a WOB of from about 2,000 lbs, aDE Power/Area of about 470 W/cm², and an ME Power/Area of about 250W/cm²; and, combinations and variations of these.

Many other uses for the present inventions may be developed or realizedand thus, the scope of the present inventions is not limited to theforegoing examples, uses conditions, and applications. For example, inaddition to the forgoing examples and embodiments, the implementation ofthese directed/mechanical energy processes may find applications in downhole tools, and may also be utilized in holes openers, perforators,reamers, whipstocks, and other types of boring tools.

The present inventions may be embodied in other forms than thosespecifically disclosed herein without departing from their spirit oressential characteristics. The described embodiments are to beconsidered in all respects only as illustrative and not restrictive.

1. A method of directed energy mechanical drilling comprising: a.providing directed energy to a surface of a material; b. providingmechanical energy to the surface; and, c. wherein the ratio of directedenergy to mechanical energy is greater than about 5; and, d. whereby aborehole is advance through the surface of the material.
 2. A methoddirected energy mechanical drilling comprising: a. providing directedenergy to a surface of a material; b. providing mechanical energy to thesurface; and, c. wherein the ratio of directed energy to mechanicalenergy is greater than about 10; and, d. whereby a borehole is advancethrough the surface of the material.
 3. A method of directed energymechanical drilling comprising: a. providing directed energy to asurface of a material; b. providing mechanical energy to the surface;and, c. wherein the ratio of directed energy to mechanical energy isgreater than about 20; and, d. whereby a borehole is advance through thesurface of the material.
 4. A method of directed energy mechanicaldrilling comprising: a. providing directed energy to a surface of amaterial; b. providing mechanical energy to the surface; and, c. whereinthe ratio of directed energy to mechanical energy is greater than about40; and, d. whereby a borehole is advance through the surface of thematerial.
 5. A directed energy mechanical drilling comprising: a.providing directed energy to a surface; b. providing mechanical energyto the surface; and, c. wherein the ratio of directed energy tomechanical energy is greater than about 2; and, d. whereby a borehole isadvance through the surface of the material.
 6. A method of directedenergy mechanical drilling comprising: a. providing high power laserdirected energy to a surface of a material; b. providing mechanicalenergy to the surface; and, c. wherein the ratio of high power laserdirected energy to mechanical energy is greater than about 5; and, d.whereby a borehole is advance through the surface of the material.
 7. Amethod directed energy mechanical drilling comprising: a. providing highpower laser directed energy to a surface of a material; b. providingmechanical energy to the surface; and, c. wherein the ratio of highpower laser directed energy to mechanical energy is greater than about10; and, d. whereby a borehole is advance through the surface of thematerial.
 8. A method of directed energy mechanical drilling comprising:a. providing high power laser directed energy to a surface of amaterial; b. providing mechanical energy to the surface; and, c. whereinthe ratio of high power laser directed energy to mechanical energy isgreater than about 20; and, d. whereby a borehole is advance through thesurface of the material.
 9. A method of directed energy mechanicaldrilling comprising: a. providing high power laser directed energy to asurface of a material; b. providing mechanical energy to the surface;and, c. wherein the ratio of high power laser directed energy tomechanical energy is greater than about 40; and, d. whereby a boreholeis advance through the surface of the material.
 10. A directed energymechanical drilling comprising: a. providing high power laser directedenergy to a surface; b. providing mechanical energy to the surface; and,c. wherein the ratio of directed energy to mechanical energy is greaterthan about 2; and, d. whereby a borehole is advance through the surfaceof the material.
 11. The method of claim 6, wherein the high power laserdirected energy has a power of at least about 40 kW.
 12. The method ofclaim 8, wherein the surface is not substantially melted by the laserenergy.
 13. The method of claim 8, wherein the mechanical energy isprovided by a bit having a weight-on-bit less than about 2000 pounds.14. The method of claim 9, wherein the mechanical energy is provided bya bit having a weight-on-bit less than about 1000 pounds.
 15. The methodof claim 11, wherein the mechanical energy is provided by a bit having aweight-on-bit less than about 1000 pounds.
 16. The methods of claim 9,wherein the mechanical energy is provided by a bit having aweight-on-bit less than about 2000 pounds and wherein the borehole isadvanced at a rate of penetration of at least about 10 feet per hour.17. The methods of claim 11, wherein the mechanical energy is providedby a bit having a weight-on-bit less than about 2000 pounds and whereinthe borehole is advanced at a rate of penetration of at least about 10feet per hour.
 18. The methods of claim 6, wherein the high power laserdirected energy has a power of at least about 20 kW and the mechanicalenergy is provided by a bit having a weight-on-bit less than about 2000pounds and wherein the borehole is advanced at a rate of penetration ofat least about 20 feet per hour.
 19. The methods of claim 8, wherein thehigh power laser directed energy has a power of at least about 20 kW andthe mechanical energy is provided by a bit having a weight-on-bit lessthan about 2000 pounds and wherein the borehole is advanced at a rate ofpenetration of at least about 20 feet per hour.
 20. The methods of claim10, wherein the high power laser directed energy has a power of at leastabout 20 kW and the mechanical energy is provided by a bit having aweight-on-bit less than about 2000 pounds and wherein the borehole isadvanced at a rate of penetration of at least about 20 feet per hour.21. The methods of claim 8, wherein the high power laser directed energyhas a power of at least about 50 kW and the mechanical energy isprovided by a bit having a weight-on-bit less than about 2000 pounds andwherein the borehole is advanced at a rate of penetration of at leastabout 20 feet per hour.
 22. The methods of claim 6, wherein themechanical energy is provided by a bit having a weight-on-bit less thanabout 2000 pounds and wherein the borehole is advanced at a rate ofpenetration the rate of penetration of at least about 20 feet per hourthrough material having an average hardness of about 20 ksi or greater.23. The method of claim 6, wherein the borehole is advanced for greaterthan about 500 feet.
 24. The methods of claim 9, wherein the borehole isadvanced for greater than about 5,000 feet.
 25. A method of advancing aborehole in the earth using high power laser mechanical drillingtechniques, the method comprising: a. directing laser energy, in amoving pattern, to a bottom surface of a borehole in the earth; b.heating the earth with the directed laser energy to a point below themelting point; c. providing mechanical energy to the heated earth; d.wherein the ratio of laser energy to mechanical energy is greater thanabout 2; and, e. whereby the borehole is advanced
 26. The method ofclaim 25, wherein the laser energy has a power of about 20 kW orgreater.
 27. The method of claim 25, wherein the power/area of the laserenergy on the surface of the bottom of the borehole is about 50 W/cm² orgreater.
 28. The method of claim 25, wherein the power/area of the laserenergy on the surface of the bottom of the borehole is about 75 W/cm² orgreater.
 29. The method of claim 25, wherein the power/area of the laserenergy on the surface of the bottom of the borehole is about 100 W/cm²or greater.
 30. The method of claim 25, wherein the power/area of thelaser energy on the surface of the bottom of the borehole is about 200W/cm² or greater.
 31. The method of claim 25, wherein the power/area ofthe laser energy on the surface of the bottom of the borehole is about300 W/cm² or greater.
 32. The method of claim 29, wherein the mechanicalenergy is provided by a bit having a weight-on-bit less than about 2000pounds.
 33. The method of claim 30, wherein mechanical energy isprovided by a bit having a weight-on-bit less than about 1000 pounds.34. The method of claim 28, wherein the mechanical energy is provided bya bit having a weight-on-bit less than about 2000 pounds and wherein theborehole is advanced at a rate of penetration of at least about 10 feetper hour.
 35. The method of claim 28, wherein the mechanical energy isprovided by a bit having a weight-on-bit, wherein the weight-on-bit isless than about 2000 pounds and wherein the borehole is advanced at arate of penetration of at least about 20 feet per hour.
 36. The methodof claim 30, wherein the mechanical energy is provided by a bit having aweight-on-bit less than about 2000 pounds and wherein borehole isadvances at a rate of penetration of at least about 10 feet per hourthrough material having an average hardness of about 20 ksi or greater.37. The method of claim 30, wherein the mechanical energy is provided bya bit having a weight-on-bit less than about 2000 pounds and wherein theborehole is advanced at a rate of penetration of at least about 20 feetper hour through material having an average hardness of about 20 ksi orgreater.
 38. The method of claim 36, wherein the borehole is advancedfor greater than about 1,000 feet.
 39. A method of laser-mechanicaldrilling a borehole in a formation having at least 500 feet of materialhaving a hardness greater than about 30 ksi, the method comprising: a.providing a laser-mechanical bit into a borehole, the laser-mechanicalbit in optical communication with a high power laser beam source; b.rotating the laser-mechanical bit against a surface of the boreholewhile propagating a laser beam against the borehole surface; with an RPMof from about 240 to about 720, a WOB of less than about 2,000 lbs, a DEPower/Area of about 90 W/cm² to about 560 W/cm², and an ME Power/Area ofabout 4 W/cm² to about 250 W/cm²; c. whereby the borehole is advanced atan ROP of at least about 10 ft/hr.
 40. A method of laser-mechanicaldrilling a borehole in a formation having at least 500 feet of materialhaving a hardness greater than about 30 ksi, the method comprising: a.providing a laser-mechanical bit into a borehole, the laser-mechanicalbit in optical communication with a high power laser beam source; b.rotating the laser-mechanical bit against a surface of the boreholewhile propagating a laser beam against the borehole surface; with an RPMof from about 600 to about 800, a WOB of less than about 5,000 lbs, a DEPower/Area of about 40 W/cm² to about 250 W/cm², and an ME Power/Area ofabout 200 W/cm² to about 3000 W/cm²; c. whereby the borehole is advancedat an ROP of at least about 15 ft/hr.
 41. A method of laser-mechanicaldrilling a borehole in a formation having at least 500 feet of materialhaving a hardness greater than about 20 ksi, the method comprising: a.providing a laser-mechanical bit into a borehole, the laser-mechanicalbit in optical communication with a high power laser beam source; b.rotating the laser-mechanical bit against a surface of the boreholewhile propagating a laser beam against the borehole surface; with an RPMof from about 600 to about 1250, a WOB of from about 500 to about 5,000lbs, a DE Power/Area of about 90 W/cm² to about 570 W/cm², and an MEPower/Area of about 40 W/cm² to about 270 W/cm²; c. whereby the boreholeis advanced at an ROP of at least about
 10. 42. A method oflaser-mechanical drilling a borehole in a formation having at least 500feet of hard rock material, having a hardness greater than about 20 ksi,the method comprising: a. providing a laser-mechanical bit into aborehole, the laser-mechanical bit in optical communication with a highpower laser beam source; b. rotating the laser-mechanical bit against asurface of the borehole with an RPM of about 250, a WOB of from about1,000 lbs, a DE Power/Area of about 370 W/cm², and an ME Power/Area ofabout 40 W/cm²; and, c. whereby the borehole is advanced at an ROP of atleast about 20 ft/hr.
 43. A method of laser-mechanical drilling aborehole in a formation having at least 500 feet of hard rock material,having a hardness greater than about 20 ksi, the method comprising: a.providing a laser-mechanical bit into a borehole, the laser-mechanicalbit in optical communication with a high power laser beam source; b.rotating the laser-mechanical bit against a surface of the borehole withan RPM of from about 720, a WOB of from about 2,000 lbs, a DE Power/Areaof about 190 W/cm², and an ME Power/Area of about 250 W/cm²; and, c.whereby the borehole is advanced at an ROP of at least about 50 ft/hr.44. A method of laser-mechanical drilling a borehole in a formationhaving at least 500 feet of hard rock material, having a hardnessgreater than about 20 ksi, the method comprising: a. providing alaser-mechanical bit into a borehole, the laser-mechanical bit inoptical communication with a high power laser beam source; b. rotatingthe laser-mechanical bit against a surface of the borehole with an RPMof from about 720, a WOB of from about 2,000 lbs, a DE Power/Area ofabout 370 W/cm², and an ME Power/Area of about 250 W/cm²; and, c.whereby the borehole is advanced at an ROP of at least about 50 ft/hr.45. A method of laser-mechanical drilling a borehole in a formationhaving at least 500 feet of hard rock material, having a hardnessgreater than about 20 ksi, the method comprising: a. providing alaser-mechanical bit into a borehole, the laser-mechanical bit inoptical communication with a high power laser beam source; b. rotatingthe laser-mechanical bit against a surface of the borehole with an RPMof from about 720, a WOB of from about 5,000 lbs, a DE Power/Area ofabout 290 W/cm², and an ME Power/Area of about 240 W/cm²; and, c.whereby the borehole is advanced at an ROP of at least about 20 ft/hr.46. A method of laser-mechanical drilling a borehole in a formationhaving at least 500 feet of hard rock material, having a hardnessgreater than about 20 ksi, the method comprising: a. providing alaser-mechanical bit into a borehole, the laser-mechanical bit inoptical communication with a high power laser beam source; b. rotatingthe laser-mechanical bit against a surface of the borehole with an RPMof from about 1,200, a WOB of from about 500 lbs, a DE Power/Area ofabout 470 W/cm², and an ME Power/Area of about 100 W/cm²; and, c.whereby the borehole is advanced at an ROP of at least about 30 ft/hr.47. A method of laser-mechanical drilling a borehole in a formationhaving at least 500 feet of hard rock material, having a hardnessgreater than about 20 ksi, the method comprising: a. providing alaser-mechanical bit into a borehole, the laser-mechanical bit inoptical communication with a high power laser beam source; b. rotatingthe laser-mechanical bit against a surface of the borehole with an RPMof from about 720, a WOB of from about 2,000 lbs, a DE Power/Area ofabout 470 W/cm², and an ME Power/Area of about 250 W/cm²; and, c.whereby the borehole is advanced at an ROP of at least about 30 ft/hr.48. A method of laser-mechanical drilling a borehole in a formation, themethod comprising: a. providing a laser-mechanical bit into a borehole,the laser-mechanical bit in optical communication with a high powerlaser beam source; b. applying from the high power laser beam source ahigh power laser beam to a surface of the borehole, wherein the highpower laser beam generates an intensity ranging from about 150 to about250 W/cm² on a surface of the borehole for an elapsed time sufficient tocause a surface temperature rise in the range from about 400 degrees C.to about 1,000 degrees C., whereby a laser applied surface is formed; c.applying a mechanical force to the laser applied surface, wherein themechanical force generates an intensity ranging from about 30 to about250 W/cm² to remove the laser applied surface of the borehole.